How to finish my lapstrake canoe?

[dmede]

Im preparing to sand and prep my 15' glued lapstrake canoe. I will be sealing the outside with epoxy and also using epoxy fairing compound to fill in any lowspots etc. and then probably paint with ???

I have a few of questions that I'm hoping some of you can help me with:

1) does the epoxy thickened with fairing filler go on after the sealing coats of epoxy or before (on the sanded wood)?

2) what inexpensive paints will go over the epoxy? i'm looking into using house paints as others on the forum have suggested before. any special prep that needs to be done for this?

thanks.

[JimD]

dmede, I always like to wet out the thirsty wood with unthickened epoxy so it can soak in a bit (meaning soak in as much as possible)and then before the epoxy cures add the thickened fairing epoxy mix over top.

As for paint the discussion never ends but keep in mind at this point the paint is really only adding uv protection for the epoxy and adding colour to your boat. If cost is an issue almost any exterior house paint will do including waterbased latex. After the epoxy fairing compound has cured wash off any possible blush, sand fair making sure there are no smooth, glossy areas of epoxy left, then prime and paint.

[Todd Bradshaw]

Why apply cheap paint over $60 per gallon epoxy? Sounds like you need to pay Mr. Kirby's website a visit. Some fillers, like those containing microballoons, should be topcoated with resin before painting. Sanding the filler breaks the hollow spheres open, leaving little pockets of air which can spoil the paint job. There are also fillers like WEST system microlight which sand easily, but which should not be used under dark colors since they have problems when the surface heats up in the sun. Most of the manufacturers will warn you if such a problem exists with a particular filler.

[dmede]

Thanks Jim. Whats the best method for applying the fairing epoxy? I'm assuming I'll need to spread it on with a plastic spreader. Also, any tips on applying the full coats of regular epoxy? Ive been using foam brushes to apply epoxy to the laps but they fall apart too quickly for large areas. Will a foam roller work ok?

Thanks,
Dave

[videoguy]

Dmede I like to use those cheep brushes with the wood handles the ones that sell for .80 cents at home depot.I use cider vinagar to clean them after use. Some guys just throw them out after use but I find they work better after one or two uses. The stuff that remains in the brush after cleaning stops loose brisles from coming out and messing up the finish coats of epoxy. smile.gif ...Phil

[NormMessinger]

I prefer to fair over cured epoxy, the reason being, the epoxy evens out the hardness of the wood so when you sand the fairing you are not as likely to cut into the softer wood. This is especially true with fir plywood which should not be sanded at all prior to saturation. Lacquer putty from the auto paint store is handy for filling pin holes and little dings after the primer coat has revealed all that you could not see before. Always test you paint on a small patch of epoxy to be sure it will cure before you find out the hard way that it will not.

[JimD]

Well, dmede, there's four replys with four different answers for you :D ... What will you be thickening the epoxy with?

[D Gobby]

For what it's worth I'm using Kirbys paint over CPES on my day sailor. Did the Angelique work out for you?

Darrel

[Aramas]

I've found that rather than using several coats of epoxy (which just adds weight by building up on the areas already sealed) I just use one, but keep adding more as it soaks in and the area gets a dry look to it - just make sure it's slow curing. It's done when the entire surface has a mirror like shine all over.

My el cheapo brush/spreader method is just to use thin strips of packing foam folded over the end of a ply or plasic spreader and stapled on. Costs nothing and works well. Use lots of staples

Q-Cell/microballoons (expanded quartz) seems to be a good filler. You know the deal with continuing to add the filler until the epoxy mixture becomes thixotropic? (ie it doesn't sag under gravity - it's like whipped cream). The last thing you want is for the filler to sag. When it's right it looks like really glossy white cream.

It sands really easy - just make sure you use a large flexible pad.

One last light coat of epoxy and another light sand should give a good base for paint. I'd be inclined to use an ordinary outdoor paint for a canoe, since it will get knocked around and probably need recoating every season - or at least touching up. Go easy on the paint though - it adds a lot of weight.

[NormMessinger]

Heh heh heh...! Now eight different answeres. But that's the beauty of this place, right George? Keep asking until you get the answer you want. LOL (as Cleek would say)

But I should have asked, maybe we all should have, "What needs fairing?" Are we advising on 10' and under blemishes (filling rather than fairing) or something a critical observer might see from 30'?

[dmede]

Boy it's just like christmass, you go to sleep and when you wake up... your boat related questions have all been answered! Great info.

Jim, I'm thickening with West Systems 407 fairing filler. It's not the super light one, which will loosen up woth too much heat. Since I intyend to paint the canoe a rich dark blue or red I figured that would not work too well.

Darell, thanks again for the angelique. I'm going to be glueing on the last two planks this weekend (that only took a year of my life). i guess the keel strip will be next, and then the cutwaters. I'm still torn between laminating and steam bending but I should have it all figured out by saturday. I'd like to find some way of using some of that wood inside where it will be left bright to show off how nice it looks.

Norm, my molds were not as good as they should have been so there are a few spots that seem to sag in at the stations. the sags are gentle and long so i figured it was ideal for fairing. i plan to scrape on the fairing epoxy down the length of each plank and then sand smoothe and fair once its set. migth be over kill though huh?

[NormMessinger]

Ah so. Would a casual observer notice? I'm leary of microballoon fairing thicker than 1/8" or so but that is a bias from building my Long EZ. Are you going to be able to share pictures later on?

Best.

[dmede]

hard to describe how noticable it is, i mean i notice but ive been looking at it for a while now. and of course it's only at certain angles otherwise she looks pretty nice (for a first boat). i don't think the remaing fairing epoxy would be more than 1/8 after sanding. probably more like 1/16 in most places. in certain respects i'm doing it just to see what happens. i plan to build again, of course, so i am really using this boat as a primer to learn techniques for a more difficult boat. i'll have some construction pics up on image station in a few days actually, and then more as i go along i hope. i'll post a link later.

thanks.

[Keith Wilson]

What's it made out of? Pretty decent plywood, I assume. I'll add another opinion just to confuse things. I don't like to use epoxy as primer. IMHO an unreinforced thin layer of epoxy doesn't do much to protect the wood. Fiberglass cloth in epoxy/glass sheathing is as much to reinforce the epoxy layer, allowing it to be thicker, (think rebar) as it is to strengthen the structure. A thin layer of epoxy alone cracks and leaks. Also, I have had trouble with enamel paint on epoxy not drying correctly, and no, it wasn't amine blush. It may have been due to a slight excess of unreacted hardener.

If it were my boat, I'd dribble unthickened epoxy onto the plank laps to seal the plywood end grain, fill any dents and goofs with epoxy and microballoons, slather the thing with CPES to stick the paint down, then prime and paint.

Kirby's paint is very nice. I've also had pretty good luck with water-based porch and floor paint, which is considerably harder than normal house paint.

[AndyFarquhar]

Why waste money on coating the boat with epoxy? I have built several glued lapstrake canoes. I follow Tom Hill's advice and paint with paint; glue with glue. I have never coated the inside or outside with epoxy. I've always found that the lap joints are sealed well with epoxy during the gluing process. If I finish bright, I use varnish. If I paint, I prime then paint on a coat or two of good enamel.

I have never had any problems with not sealing the whole boat with CPES or epoxy. I know that one of these boats (the one I kept)is stored for nine months of the year, upside-down on saw horses outside. During the winter, I hang it from the shop's rafters. A boat which I finished bright and sold is stored year-round outside in Western PA.

Regards

Andy

[dmede]

are there no strength or maintenance advantages to giving the entire hull a coat or two of straight epoxy?

i just emailed the designer with this question and he said the same, that it didn't need to be coated, except perhaps the keel for extra abrasion resistence. i still kinda want to do it. even if it's not neccesary, are there any advantages or disadvantages (besides cost, i already have the epoxy)?

[ 10-28-2003, 07:37 PM: Message edited by: dmede ]

[Tom M.]

I'll second Andy's opinion. I don't see the need to coat with epoxy.

[Aramas]

You have to fill the grain with something, and paint will soak in a lot more than epoxy will. It's probably not actually necessary, but I would do it anyway. Unless of course you have ply made from excellent wood (like the mahogany ply from the 50's and 60's). Perhaps I'm just being overly cynical, but I consider most modern plywoods to be little more than woodgrain paper mache ;)

Hell, why not ditch the epoxy altogether and use a hot glue gun for the joints. Just don't paddle further from shore than you can swim tongue.gif

[ 10-29-2003, 06:59 AM: Message edited by: Aramas ]

[Keith Wilson]

Oh c'mon now. . . Not slathering the entire boat with epoxy is in no way comparable to using hot-melt glue for the lap joints. And, yes, you're being overly cynical. Although marine douglas fir ply has gotten significantly worse in recent years, good hardwood ply is readily available. If he used plywood that's like "wood-grain papier-mache", coating it with epoxy is sure as hell not going to help, and he should probably get out the matches and marshmallows now before somebody gets hurt.

Disadvantages to coating a lapstrake plywood canoe with epoxy:

- Higher cost
- More work, both applying and fairing
- Possible painting problems initially
- Definite problems stripping and refinishing a few years down the road

OTOH, except for making it harder to strip the paint and refinish, it probably won't do any harm, so if you want to, why not? If it were me, though, I'd save the epoxy for my next project.

[John Bell]

I vote for sealing the plywood with Interlux 1026 Primer/Sealer instead of expoxy. It works great for surfaces that will be painted or varnished.

Epoxy coating without glass is a waste of time, IMO. However, I'm a lone voice in the wilderness on the subject.

[dmede]

yeah, i thought that might get a few mixed reasponses ;)

just so you know, the wood is very nice 6mm okume marine ply. okume as i understand it has low rot resistance so maybe i should epoxy? i'll figure it out when the time comes i guess. for now i need to get the last two planks on and start milling the wood for the cutwaters and keel strip.

here's a link to a few pics: http://www.imagestation.com/album/?id=4288734459&congratulation_page=Y

not much there, i'll put a few more pics up in a bit.

thanks all.