Monday, July 30, 2007

Trial-fitting of wingnet rails

It was a late night at work for me so I only had about an hour to work on the boat. Generally speaking I hate to do sanding with only that much time available, so I worked instead on trial-fitting the rails. Some folks have been asking me about what the rail-to-float geometry looks like, so these pictures should illustrate how it goes together.

The below picture shows my plan for holding the rails in place while I'm gluing them down (the 2"x4" wood will be covered in masking tape, just in case). I am going to glue the rails on in two phases: the rail-to-deck flat joins first, followed by the under-rail-to-float-edge. That way I can control the rail positioning exactly during each phase.

A view from the long end (the rear of the rail is not clamped down so it torqued out of position a bit, which is why it doesn't look parallel to the float centerline):

And one from underneath:

I need to trim off the excess on the bottom of the under-rail supports, and you can see the line I drew on the rear-most support in the above picture. Anyway, hopefully I'll get the rails all glued and taped on this week, and be fairing by Friday.

One other thing I forgot to mention last night. My HVLP spray gun came with a 1.1mm nozzle\needle combination. The literature for Alexseal's high-build primer says you should use a 2.2mm set -- wow. I couldn't even find an Accuspray "Prokit" in that size, so I settled for a 1.5mm set. Long story short, when I tried to spray with the 1.5mm nozzle, it felt like I was guiding a fire-hose (and this is what contributed to most of the overspray, I think). After my first coat of high-build I switched back to the 1.1mm nozzle (guidelines be darned) and it was much better. When I bought the HVLP kit, the technical guy at AxisPro told me that the default nozzle was "good enough" for most applications and based on this experience I guess he was right.

One more comment: Saturday's high-build spraying was my first opportunity to use Alexseal's "primer accelerator", and I was curious to see how much of a difference it would make. Well, when I sanded down the high-build on Sunday, the primer was nice and hard, and I had much less clogging of the paper to deal with. Two thumbs up! :-)

Sunday, July 29, 2007

Wingnet rails, part...uh, never mind

A brief post to update progress this week.

My wingnet rails are now faired and primed. Earlier this week I attached the underrail supports:

I then spent some time fairing the support attachment points seen above (but not much time: my main fairing goal for underneath the rails was to leave them reasonably smooth enough that someone reaching a hand underneath there won't get cut).

Yesterday I applied two coats of the highbuild primer; today I sanded that down, then put on two coats of the finish primer:

Tip: when spray painting in your garage, even with a "low overspray" HVLP system, you should lean toward more plastic masking, not less.

Although progress on the floats is mostly stalled until the wingnet rails are done, I did get the deck attachment points prepped. It's not very fun grinding down through primer and fairing compound that you've spent hours and hours of sanding on:

I've also been trying to use this time to catch up on other stuff. Here's the last of the laminate (two extra layers of C on the front part) being bagged for the bow web:

I'm now ready to start cutting slots in the bow web.

I also bagged my first daggerboard case half. Here I am in the middle of lamination, before the core went on; if you look carefully you can see the UD glass:

Here it is with the bag on (got good seal on this one):

And here's a picture of the inside of it after unmolding (forgot to put peel ply against the mold first, but it looks ok):

Everything went fine except for one thing which I didn't notice until I unmolded it today: it looks like I left the foam core just a tiny bit too wide, and near the aft upper edge it butted out past the mold a small amount:

It's mistakes like this that makes me feel like a blithering idiot, but obviously I haven't made enough mistakes to learn the lesson yet. I've sent Ian an email asking for advice, to see if he'd keep the part or toss it. We'll see what he says.

Other than all of the above, I've been studying the plans every chance I get, to get ready for starting the main hull.

Tuesday, July 24, 2007

Wingnet rails, part 5

I can't believe it's already late July -- the summer feels half-way over, and I still haven't painted my floats. Ouch. Anyway, this is just a short post to update my progress. I wish I had more to report, but work and family have been keeping me pretty busy.

Last Monday or Tuesday evening, I re-primed my port float with four coats (first coat in gray, as before). I then spent the rest of the week sanding the floats back down to 400 grit. Really this went pretty fast. I attribute this to the fact that the sprayed-on primer lays down really, really nice, and I was able to use my electric sander with 220 grit right from the start. With my earlier rolled-on primer coats, I ended up with much stippling in the surface that required a lot of longboarding to cleanup; I think I wasted a lot of primer that way. To be fair, the Alexseal rep had warned me that their primers weren't really designed for rolling. I won't ever roll the primer on again.

The gray primer base coat helped a ton, especially around the edges (keel, bow, transom, etc). It was a pain to have to clean the gun and mix new primer right after the first coat, but I loved that feeling of security you get when you can visibly tell you're "getting close". Even so, I did get a couple of sand-thru spots, one on a transom edge and one a keel area near a bow, due to carelessness. Not a big deal compared to how many I had before. I won't post any pictures of the re-sanded floats, since they are fairly boring at this point.

I procrastinated somewhat on the fairing of my wingnet rails because I didn't want to deal with sanding on these long floppy parts. On Sunday I finally got the job started, putting on the first coat of fairing compound:

And today I got around to sanding:

This was followed by a second thin coat of fairing compound, to fill in the imperfections. (Hmm, I seem to remember this procedure from somewhere? :) I believe I'll need at least three fair-sand passes on the outside (visible) parts of the wingnet rails, but I'm still debating how far I want to take the under-side though, since it will be rarely seen.

Sunday, July 15, 2007

Wingnet rails, part 4, and more finish primer

Saturday I worked on marking and trimming the wingnet rails. Ian doesn't give exact measurements for this, but by carefully measuring the dimensions on the deck layout plan sheet and using the scale factor to convert, it's not too hard to figure out what it should look like. I also spent some time looking the rails over while they sat in place on the floats, and doing some rough-in marks to make sure they would clear the access hatches:

Then I took them back in the garage, and drew in the final cut-out marks. I didn't seem to have anything suitably round in the garage for making the quarter-radiuses, so I improvised with a can of soup:

Yeah, I know clam chowder would have been more appropriate but we were out-of-stock -- I'll just have to deal with the shame.

After some jigsaw work, voila:

I also cut the rails down length-wise so that they ended 2.5" inside each beam location index dowel. I did this without much thinking though, and I now think I should have left them a bit longer just in case the beams turn out narrower than I expect. I'll save the cutoffs and in the worse case maybe I can laminate them back together.

I've put some thought into the sequence I should follow for attaching the rails to the floats. Bear in mind, I still need to scuff, re-prime, and re-sand my floats - and I think the wingnet rails could be easily damaged if they are attached to the floats while I'm turning them this way and that way, in order to sand the sides. So I'm going to do things in this order:

  1. Scuff the floats back up to 150 grit.
  2. Re-prime the floats.
  3. Sand the floats back down to 400 grit.
  4. Pre-fair the wingnet rails (leaving the taping surfaces as raw glass).
  5. Locate the wingnet rail attachment points, grind those areas back down to glass, and laminate the rails to the floats.
  6. Fair the rail attachment points and prime them. All of the attachment points are on or near the deck of the float, so I can leave the floats upright for this step.
  7. Paint the entire float, including the wingnet rail.

Once I'd decided on the above, this made scuffing and re-primering a big priority again. So I spent the last half of my Saturday work day, sanding down my floats to 150 grit again.

Today was a bit slow due to some family events. However, I did get my HVLP system setup again, and I put four coats of the finish primer on my starboard float. As I mentioned before, the first coat was gray to serve as a warning layer when I'm sanding (so I don't go too far next time):

My spray gun worked really well. The primer coats turned out much smoother than when I did them with the roller (when I start sanding, I think I'll be able to start right at 220 grit). My nozzle size is 1.1 mm, which is just below the range recommended by Alexseal (1.2-1.6mm). For whatever reason, it looked like the primer coats were going down very thin, which is why I continued on with three coats of white.

I need to get some more lighting in the tent -- otherwise it is very hard to see sometimes, where you've sprayed and where you haven't. For primer it's not such a big deal, but I imagine this could make things really hard for the top-coat application. I do happen to have a dual halogen worklight that I bought last winter -- I'll give that a try next time.

I also learned some lessons about hose management; it's easy to forget about the hoses, and I dragged them through the primer a couple times. Easy to fix, but I'm really glad I'm getting this practice opportunity now. I also used cable-ties to tie the sprayer and the respirator hoses together, which helped a lot when dragging them around.

I'm not sure I'm totally happy with the full-face respirator. On the plus side, it's easy breathing and it doesn't fog up. On the down side, it's hot as hell, fills up with sweat really fast, and it's hard having your vision constricted. I think tomorrow I'll order the half-face version, so I can compare.

On the 4th of July I had gotten some advice from my brother-in-law, that you should vary your pass directions. Eg, first pass uses a side-to-side motion with a vertical fan pattern, second pass uses a up-and-down motion with a horizontal fan pattern. I didn't really think this would be necessary, but boy was I wrong -- even when you're doing a good job of overlapping your passes, it's still quite easy to see pass "lines". So I flipped directions for my 2nd coat of white, and it did seem to help.

BTW, my HVLP system is looking much more manly now; not so nice and shiny anymore with white and gray dusty overspray on my hoses.

Friday, July 13, 2007

Wingnet rails, part 3

[Hopefully this won't turn in a long-running series...e.g., "Wingnet rails, part 17"...]

Yesterday after work I got to work unmolding the first upper support rail. This turned into a bit of a job. I had cut the glass a bit too long, and it had been tucked underneath the bottom of the molds on the ends, and cured in that position. To make it worse, I hadn't done too good a job on masking off the bottom of the mold. The glass also wrapped around the bottom of the lower lip somewhat. I pried and hacked and even smacked the end-wrapped parts with a hammer, but they weren't budging. So I cut off the ends of the laminate, mold and all. This is what the chopped-off parts looked like:

This strategy worked great and I was left with this to unmold:

Here I did a sanity check against the pattern:

Not perfect, but it could be how I took the picture: holding the paper still while snapping the shot one-handed. Even so it looks pretty darn close except for that lower lip, but I don't think it will be a problem.

After prying, prying, and more prying, eventually I got it popped loose. Then I laid it aside because I wanted to focus on getting the second main support rail laminated and bagged. This went pretty smoothly -- it always does the second time around.

Tonight after work I unmolded the second support rail; it was actually a bit easier than the first one, since I'd reduced the width of my glass in both dimensions, so I got much less "wrap-under" on the mold but I still found it necessary to chop an inch or so off each end. Then I got busy removing the peelply from both rails; I'd forgotten how much fun this can be (not):

Eventually though it was all done and my support rails are now ready to be trimmed and attached to the floats:

That's all for today; it's been a long week between both day-job work and boat-job work. Tomorrow I'll get started trimming the rails down, and (cringe) grinding my floats back down to glass in the necessary spots.

Finally, if someone local to the area would like to take ownership of my wingnet rail molds, I'd be happy to give them away - otherwise they will get chopped to pieces in a week or so since I don't have room to store them. Even after chopping a little bit off of each end, the main support rail mold is still 9' 8 1/2" long - should be plenty I think. Email me and let me know if you want them - you pick up.

Wednesday, July 11, 2007

Wingnet rails, part 2

Today after work I un-molded the support rail. Here's how it turned out:

Looks okay, but it felt quite thin...

...and not quite as stiff as I was expecting. As soon as I picked it up, I said to myself "shoulda done that fifth layer of glass". The plans only called for four, but I had a fifth layer ready to go yesterday while doing the laminate. I almost put that extra layer of glass on, but at the last moment decided to keep faith in Ian and keep it "per-plan". Logically that has to be the right decision, but it's hard to resist the urge to "just beef it up a little".

Then it was on to the main support rail. First I sanded it all down, got rid of the rough edges, and smoothed over the corners including running a small round-over bit down the one right angle corner. Here it is after covering it up with masking tape:

Then it was time to prep the rest of the vacuum bag materials: two layers of peelply, release film, breather, and bag film with mastic attached. Oh yeah, plus the glass; it's fun cutting four 10' long pieces as they come off the roll:

Finally it was time to wet-out the glass. Working with 10' lengths is fun. Here I am wetting out and rolling up the first piece:

See all those little strings of glass hanging off? It's times like this that I say to myself "why didn't I decide to use the glass with a backing mat so I don't have to deal with this crap?" :) Here is the form with the second or third layer of glass rolled out onto it:

Originally I thought I would make a real bag out of two pieces of bagging film, but changed my mind because there were a lot of little sharp edges underneath the form; many were in hard-to-reach spots and I was worried that these would poke holes in the bag. So instead, I bagged the form against my workbench countertop. With such an odd shape, this has some drawbacks like, will the pressure stretch the bag too far? Well it hasn't yet but we'll see; the bagging film and mastic is getting quite the workout:

The pump took a long time bringing the pressure down, and never got higher than ~22 lbs; which means the vacuum switch is useless since I have it set at a 25lb cutoff. With the bag and the mastic stretching so much I guess I can't expect much better. Anyway, I don't care if the pump gets an overnight workout as long as the part turns out good.

Tuesday, July 10, 2007

Wingnet rails, part 1

The profile of the wingnet rail and its support piece(s) is given on one of the new full-size pattern sheets. I started out with a ruler and protracter, measuring the angles and distances so I could angle-cut the pieces on my table saw using the angle guide (I just love that thing - it eliminates all the guess work). Here's my results:

I guarantee these dimensions and angles for the same amount you paid for them. :) Seriously though, I'm sure the above measurements are not perfect, but they're darn close.

I spent Monday evening ripping and sawing a 4'x8' particle board into the various pieces I would need to make the forms:

The support rail form is easy - there are only two pieces, each 3" wide, so I made a single form about 10" long. I'll make a single laminate off of that then cut two pieces out of it. I admit that I pestered Ian about this because I was skeptical that only two support rails were needed for the entire wingnet rail. He assured me that the vertical loads on the rail are relatively small and that two supports are sufficient.

The main rail will be roughly 9' long (guesstimating because I don't know how wide the beams will be) so I cut up enough pieces to make a 10' form (in 6' and 4' pieces). Here's a email response I got from Ian on how long the main rail should be:

Just leave them hanging close to the beam, I will come back to this when I have the first set of beams made and make any provision then - they may attach to the beam join flange.

Here's a woodworking tip that I learned: don't try to cut particle board with a finish (fine-tooth) blade. It will cut like crap, and makes a burning stench and even some smoke. (Thanks Bill, for loaning me the right blade -- wow, what a difference that made.) But even with the right blade, cutting particle board sucks because it produces clouds of dust. I was wearing my respirator the entire time.

Tonight after work, I got to work on constructing both forms. The weather helped out a great deal -- we had a 90degF day, I used Fast hardener, so things went really quick. Here is the support rail form, all glued together with the edges rounded over:

Here's how close I came to matching the pattern (this was taken before the edges were rounded over):

After covering the support rail form with masking tape, I went ahead and wet out the glass for it:

I actually ended up taking the glass off and laying down a piece of peelply against the first mold first, so that both sides would be nicely textured. Eventually it was all ready for vacuum:

I think this was the first time I've ever had to deal with pleats in the bag, and as you can tell it wasn't the neatest job in the world. Eventually I got it air-tight and it's out in the garage right now under 25 lbs of vacuum.

I also got a lot of work done on the main rail form. This form is more complicated than the little one above, of course. I just took it one step at a time, gluing the pieces on with epoxy and waiting for it to get to a reasonable cure before moving on the next piece (lucky the weather was so warm). I was concerned about how I would clamp the angled joins, but the epoxy grabbed the pieces fast enough that just a few minutes of holding them in place by hand was sufficient. Here's a few pictures of the construction.

First join getting glued:

As I said above, this form is 10' long, made out of 6' and 4' pieces; the joins were all staggered of course.

This is the only right angle in the form; I took advantage of this and used clamps:

Here's the completed form, back side first:

Then front:

Not too bad for two evening's worth of work. Tomorrow will be the fun part: bagging the first of two long main rail pieces.

Sunday, July 8, 2007

Pausing to build wingnet rails

I did not make much progress this weekend, and the progress I did make (sanding floats to 320 grit) appears to have been wasted effort. As mentioned before, the new plan book details how to construct the wingnet rail. The rail is two formed pieces of fiberglass, that attach together and to the deck to form a raised rail (about 5" higher than the deck); a metal extrusion rail will then be attached to the glass rail to form the outboard net attachment. Obviously in order to attach the rail to the deck, the deck will need to be ground back down to fiberglass itself. So there's no point in continuing with any fairing, primer, or paint until the wingnet rail is constructed. I got started today on making the forms for the rail pieces and will update how that went in a future post.

The Multihull Nets web site has lots of good pictures and explanations of the various net attaching mechanisms. This was helpful in getting me oriented as to how these things work. Ian does allow for another net attachment option, which is to stretch a cable between the beams and lash the net to that - but the net will not be supported and hence will droop. I decided not to go that route -- I'm a big guy and want the nets to be nice and sturdy.

Heeding advice from several folks (Tor, the Alexseal rep, and Tim in Maine) I've decided not take any chances with my sand-thru spots. The Alexseal rep said it would be okay as long as all spots were "quarter-sized or smaller", and I have many that are bigger than that. Once the wingnets are built and attached, I'll be scuffing, re-primering (with my HVLP gun!), and re-sanding both floats all over again. This time around, I think I am going to spray one coat of gray primer, followed by two coats of white - that way when I'm sanding, I'll have a guide to tell me when I'm going too far.

I was amazed with the Alexseal paint that I sprayed on my access hatch cutout. Even with a crappy sanding job, that paint is shiny as heck! And it feels really hard and tough too. This is making me very excited to see the final paint job... I think I'll sand the other access hatch down to 320-400, spray it, and take it into work as a conversation piece (I already have some raw foam and a piece of vacuum-bagged laminate in the office to help show co-workers what I'm working on - if they show interest :).

Edit: I just had to mention something that happened to me today. This morning I went down to Fisheries Supply (again) in Seattle to buy (yet again) more supplies. (The employees there are starting to recognize me and remember my name - this is bad, very bad.) I ended up asking Karen back in the sailboat area if she would send my order downstairs for me (F.S. has many items in a non-public warehouse below the main store. You tell someone what you want, and they bring it up for you in about 5-15 minutes, usually. Unfortunately, all of the Alexseal products are downstairs.) While waiting for my items, I chatted a bit with her and noticed on her business card that she is the "Sailboat Specialist". Long story short, it turns out I was talking with the first American woman to do a solo circumnavigation. Pretty cool! Yeah - I'd say she's qualified to be the Sailboat Specialist, for sure. :)

Saturday, July 7, 2007

De-virginizing the HVLP sprayer

My new HVLP sprayer arrived on Friday -- woohoo! Then on the same day, I got some email back from Alex, the Alexseal rep - he said that Alexseal does not recommend using HVLP to apply their topcoat, as the lower pressure just doesn't atomize the paint very well. (What - now you tell me?!?) This was a bit of a shocker, as their topcoat literature actually specifies the amount of coverage you can expect using HVLP (but it doesn't give HVLP-specific setup instructions). Anyway, I'm supposed to call him on Monday to discuss things in more detail.

After getting that email from Alex, I was a bit worried and went into Internet Research Overdrive (aka google search) looking for references\articles\stories of folks who have sprayed Alexseal with a HVLP sprayer. There's not much out there, at least anything with specific data. (I was looking especially for stuff like specific nozzle and air-cap sizes, spraying distance, reducer speed, etc). The best stuff I could find was from a guy named Tim Lackey, who runs a boat restoration business in Maine. Tim's focus is an older monohull design, but paint is paint and it doesn't care what kind of boat it is sprayed on. There is a lot of good info in his restoration diaries (example), and he also owns a forum that when searched (try "HVLP" or "Alexseal") comes up with lots of good info.

Here's a summary of the advice I gleaned from Tim's site and forum:
  • The biggest issue with HVLP seems to be that it produces hotter air which will tend to cause the paint to flash off quickly. Remedies include: longer hose (allows air to cool down a bit); run part of the hose through an ice-water bath; use a slower reducer than would normally be called for.
  • Due to the lower working pressure of HVLP, Tim suggested adding 10-15% reduction to the manufacturer-suggested amount. This will thin it out more and allow it atomize more easily.
  • The first coat should be very thin; then build it up with the second and third coats (this seems to be standard painting advice, regardless of whether its HVLP or not).

With the rest of the family off at a concert this evening, this was a good time for me to break in the new HVLP sprayer which arrived yesterday. Here's the parts that comprise the system:

I also paid extra to get a disposable cup system made by 3M:

This cup system uses a flexible plastic liner inside of the outer hard cup shell; when you first start spraying, it takes a few seconds to suck all of the air out of the liner, then you're spraying nothing but the paint. The advantage is that it is easier to clean up (just throw away the liner), and you can spray at any angle including upside down.

My wife had suggested that I use some cheap latex paint to learn on, but I had second thoughts on that. Why not try to learn using the real thing, (other than the 10:1 difference in expense)? So I mixed up a small batch: 4 oz of base plus 4 oz of converter. The Alexseal literature says to reduce it by 30-35%, but based on Tim's advice above, I pushed to 40% (3.2oz of reducer, as best I could measure it). I then put the turbine unit outside, hung some cardboard on the inside of the garage door, uncoiled the (stiff) new hoses, got everything ready, tested the mask, and finally attached the gun and gave it a whirl (see cardboard behind the gun, in the picture above). I also painted one of my access hatch cut-out scraps (it wasn't sanded down to 320-400 yet, but I was curious to see the paint on something better than cardboard):

My first impression is that I have a lot of learning to do, to be able to produce a quality paint job.

Thoughts beyond that:

  • There is a lot of stuff going on: trigger control; holding the gun at the right distance from the surface; holding the gun at right angles to the surface; starting\stopping each pass correctly. For best results, all of this needs to be performed instinctively.
  • To try to get a thin coat, I was instinctively pulling the gun farther back from the surface; need to stop that and play with the air and fluid adjustments instead.
  • The turbine unit is wake-the-dead loud! I think I will get some earplugs.
  • Having a fresh-air supplied mask is awesome -- very nice, easy breathing, and no fogging of the face plate.
  • Dragging two stiff hoses around sucks. Unavoidable of course, but this will probably also need some practice, to avoid bumping the hoses into the paint.
  • I am not so sure that I need extra reducer when using my system - the paint seemed awfully runny. Tim's unit (a Showtime 90) is a 2-stage turbine, and produces "only" 5 psi; my unit is a 4-stage and produces 8 psi. My guess (hope) is that the extra psi of my unit will reduce (punny) the need for more reducer.
  • Lots of experimentation will be needed to finetune my skills.
  • I wish I had sprayed all of my primer coats - I could have used all of that practice.
  • My paint color choice looks nice. :)

Cleanup of the gun was straight-forward. I was worried that I'd be scrubbing tiny holes for hours, but it was trivial: fill paint cup with some reducer, spray until clear, remove cup, remove air cap and nozzle, wash them with reducer, wash outside of gun. At least that's what the instructions say to do, so that's what I did.

Lest you think I'm discouraged after all of the above, rest assured I'm not. For my first time ever holding a spray gun, I feel like I did okay. The rest will come with practice. And if I screw up a paint job on one of my floats...well, I may not know how to spray very well, but I sure do know how to sand (so I can sand it down and start over). :)

The other thing that's happened, is that both floats are now sanded down to 320 grit. Fisheries Supply didn't have 400 grit longboard paper in stock, so I had to order some from Noah's to finish the job. Once I have it, I should be all done in one evening. At 320, the floats feel like smooth glass and have gotten a lot of their shininess back.

However, I am concerned about one thing that I need to ask Alex about when I talk to him: in several small spots, I ended up sanding through the primer coats down to the fairing compound. Granted, these spots are all very smooth and feel no different from the surrounding primer'ed areas, but will they look different once painted? Probably I also sanded through the finish primer down to the high-build in a few areas, but those spots are harder to detect. I will be a bit upset if Alex tells me I should re-prime and sand. I'd have to scuff the surfaces with 100-150 just for the primer to stick! :)

Thursday, July 5, 2007

Sanding the finish primer

As planned, on Monday night I put three coats of finish primer on the starboard float. Since then it's been back to sanding. Fun fun. At least yesterday was a holiday (happy 4th of July!) here in the USA, so I got a full day of work done.

I don't have much to report otherwise -- more sanding is about it. The finish primer starts out nice and shiny, it's almost a shame to have to knock it down:

But hey, someone's gotta do it. At least the sanding seems much easier now that I'm in the higher grits. I'm not trying to take off lots of material anymore, just enough to smooth things out. The floats are feeling buttery smooth. I don't think I will end up with a professional looking paint job, but I'll be happy so long as I'm not embarrassed by my own boat down at the boat launch.

I find that it's not as easy to keep track of where I am since the floats look and feel about the same now. I started keeping notes, so I wouldn't forget. Here's the state of things after tonight:

In the picture above, "edges" means the keel, bow edge, and deck-to-side radiuses. Those are all 100% sanded by hand, of course.

I haven't changed the bag in my Festool vacuum since I bought it, and finally got off my butt to check it this evening. Oops - probably shouldn't have waited this long:

The dust was very compacted in the bag, and it felt like it weighed about 25-30 lbs (~11-14 kg for you metric types). I'm not kidding, it was totally packed in there.

So I'm getting closer and closer to the final paint. It feels good. However the new plan book has a sheet detailing how the wingnets will attach to the floats. Basically, you have to construct a raised flange\web that is laminated to the inbound side of the float deck, in between the beams. This flange then supports the the outer edge of the wing net. Obviously this raises the question then, of when do you want to construct this flange and attach it -- before or after the initial paint goes on the float? I sent mail to Ian asking about this and will update this post with his advice once he replies.

Last bit of news, is that I've decided to spray the final topcoat after all. I've never sprayed before in my life, but I finally decided that I just could not risk wasting all of this hard sanding work on a subpar roll-and-tip job. I've ordered a Citation 4 HVLP turbine sprayer from Axis Pro; it includes a fresh-air supplied mask and an Accuspray gun. This system is near top of the line, from what I can tell, and is honestly overkill for just one project. However I have been wanting to get myself set up with a sprayer for some time now -- so it's really a long-term investment, not just a F22-specific cost. And yeah, I'm still a bit worried about the health aspects of spraying but the full-face mask should mitigate that.

I also considered one of the Turbinaire products, but I really liked the idea of having a fresh-air supply integrated with the main unit.

My brother-in-law was over visiting on the 4th; he worked in the cabinet trade as a sprayer for a long time, and was giving me lots of advice.

I'm taking Friday off from work, but don't know how much time I'll have for boat work -- I've been letting chores pile up around the house, so this will really be a catchup day. I have also submitted a request at work to take the last three weeks of August off for vacation. One of those weeks will be devoted to family time, but with any luck I should be able to make significant dent in the main hull construction.

Sunday, July 1, 2007

Finish primer applied to port float

After a few evenings and a weekend of sanding I'm finally done (cross fingers) with the high-build primer. My last act for today was putting three coats of finish primer on the port float. (I'd show a picture, but it's not very interesting - once you've seen one white primered float, you've pretty much seen them all). I'll note that I sanded the high-build primer all the way down to 150 grit, which is at the high end for the finish primer prep (they recommend 100-150 for preparing the surface). The top coat prep calls for 320-400 grit, but my floats already feel like a baby's bottom -- IMO :-) -- at 150 grit - it will be interesting to see what the extra smoothness will add (if I can even tell).

The extra coats of primer did indeed help in many bad areas, but not all. I've learned some hard lessons during the fairing of these floats. You can't depend too much on the primer, so therefore it's crucial to take your time and be really detailed when doing the initial fairing. In a few areas while fairing, I fooled myself into thinking "ah that'll be fine -- the primer will fill it in easy". Some of those turned out for the worst and needed fixing, but I'll blame it on inexperience this time. It really boils down to "pay now or pay later", and it's better (easier) to pay in the early stages. The primer sands down beautifully, but it won't look its best unless the underlying surface is fair. Let's hope I remember all these lessons when I get to the main hull.

Yesterday I put finish primer on my two test scraps, and today I sanded them down with the electric sander. (Gotta love power tools -- my arms and shoulders are aching after all that extra manual sanding this week.) The high-build is almost chalky when sanding (hence my mention last post about clogged sandpaper), but at least it was very, very quick to sand. In contrast the finish primer seems to cure hard and tough (much like the S3 primer I used on my dinghy) even after only a day of curing. I'm glad I'm switching over to the electric sander now. The Festool vacuum system works wonderfully, so that should cut down on the dust as well.

The new F22 plan book arrived on Friday. All I can say is -- Wow! As I mentioned to another future F22 builder, the new plan book has lots of minor updates, lots of new pages, and this time they were printed on a color laser printer. The pages are absolutely stomp-down gorgeous. I was actually quite pleased with the quality of the inital plans, and wasn't even dreaming of getting anything nicer. Although not 100% complete yet, there is a ton of never-before-seen details in the new book, including things like the wingnet attachments, rudder gudgeon fabrication, poptop fabrication, etc. While cool to see, it also made me stop and realize just how far away I am from being done with this project.

Tomorrow night I'll put the finish primer on the starboard float. Then I'll be busy for awhile, sanding the floats down to 320-400 grit. (I'm kinda wondering, if 400 grit would even make a difference when doing a roll-and-tip job.)