Plywood boat leaks :(

[kevinb]

Yes. Actually, I looked at the second-hand mirror, and it wasn't in terrifically good shape. I imagine it would take longer, and cost more, to make a decent boat of it than to finish my own one. So it's full speed ahead again

I've sealed up (I hope) the small leak and I've put a half-gallon of epoxy battleship paint on the outside. I'm not very keen on the colour, and I've only got another half-gallon left and I need that for the inside (it's too ugly just to varnish).

So do I need anything special to paint over epoxy paint? I'm hoping to get away with ordinary domestic exterior gloss (spirit-based), since I've got gallons of the stuff. But I've heard that enamel is also a possibility. If I can paint these over epoxy paint, do I have to wait until the epoxy is fully cured? Any advice gratefully accepted.

Originally Posted by kevinb

Yes. Actually, I looked at the second-hand mirror, and it wasn't in terrifically good shape. I imagine it would take longer, and cost more, to make a decent boat of it than to finish my own one. So it's full speed ahead again

I've sealed up (I hope) the small leak and I've put a half-gallon of epoxy battleship paint on the outside. I'm not very keen on the colour, and I've only got another half-gallon left and I need that for the inside (it's too ugly just to varnish).

So do I need anything special to paint over epoxy paint? I'm hoping to get away with ordinary domestic exterior gloss (spirit-based), since I've got gallons of the stuff. But I've heard that enamel is also a possibility. If I can paint these over epoxy paint, do I have to wait until the epoxy is fully cured? Any advice gratefully accepted.

You are tooooo fast. !!!
Epoxy has to cure properly before it should be tested to be waterproof or the like.
But now you did apply the battleship paint (that in this case could have been a proper decision, because the paint may stick on the epoxy putty better, than it would if the putty did cure to final stage).
You must not cover the dreadnought paint with anything! But if, for cosmetical purpose, you like to camouflage your result, you may smeere almost everything on it as long as there are no solvents like aceton in it. So, enamel is NONO.
But expecting a total lifetime of less than a few years, almost nothing matters.
It´s tight, thats it.
Kindest
Regards
Richard

[robherc]

I know I'm a bit late here, but early on I'd have recommended you get some lightweight 'glass tape & just polyurethane it on with a few coats of polyurethane. It's not an AMAZING way to do it, but it'd waterproof your boat (assuming you let it cure properly between coats & use a few coats), and the 'glass tape would hold it in the seams & hold the seams together. Not to mention that you'd then have the nice "stained-wood" look to the finished product.

I don't know what kind of life expectancy I'd give a boat like that, but 1-2 years of light/moderate use shouldn't be out of the picture (just be SURE to let the polyurethane cure for a FULL 12-24 hrs between coats, and 24-48 hrs before puttin' it in the water)

[kevinb]

Originally Posted by robherc

I know I'm a bit late here, but early on I'd have recommended you get some lightweight 'glass tape & just polyurethane it on with a few coats of polyurethane. It's not an AMAZING way to do it, but it'd waterproof your boat (assuming you let it cure properly between coats & use a few coats), and the 'glass tape would hold it in the seams & hold the seams together. Not to mention that you'd then have the nice "stained-wood" look to the finished product.

Thanks for the advice... if I were doing this again, I suspect I'd do everything differently. I did consider glass and poly resin, but it's just soooooo cold here -- the suppliers told me that it would be a very bad idea to apply it with temperatures < 15 Celcius. In my workshop I can just get the temperature to about 7C with continuous heating at the moment. It's not ideal for epoxy either, I guess, but my original intention was not to use any. In the end I used about 250ml, just for sealing.

Of course, I could wait till it warmed up, but I wanted to get on the water before my kids turned their attention to some new fad. They'll have me making a quadbike or something next, I guess.

Anyhow, I'm pleased to report that after three coats of battleship paint, my little boat appears to be complete watertight. For now, anyway. It's not finished, but I managed to get four people in it this morning, and even with us all stomping about and changing places and what-not it didn't collapse or let in water. So I'm feeling quite pleased with myself.

But it's jolly hard to move it with a single paddle, especially in a current, I've learned that much. Need to make some oars now. I'd also appreciate any advice on finishing off top of the plywood with trim. The easiest thing to do would be to screw/glue some hardwood strip along the top edge as a sort of gunwale, but I'd really prefer to cover the exposed edge of the plywood somehow, It's sealed, but it looks a bit naff, that's all. Mind you, the whole boat looks a bit naff, so I suppose I shouldn't be so fussy

[PAR]

There is a plastic "U" shaped piece (comes on a roll usually) that will fit over the edge of the plywood. You just buy it for the thickness ply that you have. Since you budget prevents this, the next best thing which looks better too is a piece of hardwood trim. You can notch the bottom of it to receive the plywood edge (groove) or use just a half lap kind of joint, so the end grain is covered and protected. Glue it on and you're good to go. With some varnish, it would make a nice touch that's reasonably easy to care for.

[kevinb]

Thanks. My budget would probably run to a few metres of plastic trim, although that will bring the total cost of the project up to about £20 But I prefer the idea of rebating a piece of hardwood trim as you suggest, because (a) I already have it and (b) I guess it will protect the plywood a bit better when the boat is stored on its side.

[PAR]

My most strong recommendation is to slap some trim on the puppy and let your kids have fun. Yep, they'll tear it up, but you should be use to this by now. She floats, with few if any leaks (good job, even if you got lucky, brag anyway). Enjoy your creation and good luck on your endeavors. All kids should have dads like you. Mine did, but years of therapy have fixed most of their ills in spite of my efforts. Boats are commodities, meant to be bought sold, built, burned and dragged to the land fill. You do realize they'll want a mono foiler, capable of 25 knot plus speeds next, right . . .

Originally Posted by PAR

My most strong recommendation is to slap some trim on the puppy and let your kids have fun. Yep, they'll tear it up, but you should be use to this by now. She floats, with few if any leaks (good job, even if you got lucky, brag anyway). Enjoy your creation and good luck on your endeavors. All kids should have dads like you. Mine did, but years of therapy have fixed most of their ills in spite of my efforts. Boats are commodities, meant to be bought sold, built, burned and dragged to the land fill. You do realize they'll want a mono foiler, capable of 25 knot plus speeds next, right . . .

My words.........
Thanks PAR