I did search the archives, but didn’t find exactly what I’m looking for.
I just got the 17’ canoe my dad and I (really mostly my dad–I was a teenager with important things to do) built about 25 years ago. It’s fiberglass over mahogany strips. Great looking and great paddling boat. But after 15-20 years hanging outside, the finish is dull and chalky. When you get it wet it glows like new–maybe even better than new–but when it dries it shows its age.
He used poly resin, not epoxy.
He says that when it had cured he washed it with acetone and then varnished it and waxed it.
I’d like to get it to shine and glow like it used to. His recommendation is to wash it with acetone then varnish it. I was thinking of applying a coat of clear epoxy over the whole hull (outside only–the inside is still looking great). This, in combination with some sanding, would also help smooth out some scratches and dings.
But I’m wondering how well an epoxy will stick to 25 year old resin or any varnish that’s still there.
The lazier part of me says to just clean it up really well, remove any wax that is still there (probably not much) and re-wax it with a quality wax.
Any suggestions would be most welcome.
Varnish may work, if the resin and glass
underneath are not milky. Polyester resin sometimes works out OK if a boat is treated and stored properly. There should be no special problem with quality varnish adhering to polyester.
You could strip all the exterior glass and resin off and replace with epoxy and new glass, but that doesn’t seem like a good time investment. If it still paddles well, then paddle and enjoy it.
…is as you’ve suggested - a light sanding, clean with acetone, and revarnish. I’d be cautious about using epoxy - it’s only going to be as durable as whatever it adheres to.
The application of fresh varnish should do exactly what you want - renew that nice clear finish. If it looks good when wet, it’ll look fine with fresh varnish. I use the matte finish, as it doesn’t show light scratching like the hi-gloos does…
You now have possession of one of life’s great lessons, that something of great value can be made if you invest the time. It takes vision to make your own boat.
The first canoe I built (with epoxy) turned milky. I glassed it outside and when evening rolled around and the air got moist, it turned milky. Well, that boat was in an embarrassing accident in the surf and got a big hole punched in it. When I repaired it, I stripped off all the old glass from the outside only. That left some pretty tacky looking scarred up wood under the glass on the bottom. I painted it a light tan on the bottom. It kind of looks like a waterline type of paint treatment in that the paint stops around the waterline. That is pretty effective at protecting the canoe from the effects of the sun. When the boat is in the water, it still shows the pretty wood.
When revarnishing, I scuff sand all surfaces for adhesion. I use Interlux #96. The cheap varnish is too expensive. It doesn’t last. The Badger brushes are worth their cost. West Marine sells them, if you don’t have access to a more soulful source. The last trick; a product called Penetrol. I use a quart milk carton cut off about halfway and put about 1 1/2 to 1 3/4 inch of varnish and about one or two capfuls of Penetrol. It makes the varnish lay out much better. Without Penetrol, sometimes the varnish just can’t be pulled along leading to a splotchey job.
It is a fulfilling gleam that comes from well varnished wood.
By what method did you remove the old glass? Seems like a daunting job to me, but one I need to do. Thanks.
Thanks for the good advice so far. The resin itself is not at all milky, it just lacks a proper finish to show off the wood and make people jealous like the boat did when it was new. It’s lucky that the work was done in the west, where there is little to no humidity to screw things up.
What’s acetone going to remove? What won’t it remove? Wax? Old varnish?
And how long can I reasonably expect good varnish to last before I have to do it again (on fiberglass, not wood)?
When I did a search for Interlux 96 google pointed me to Interlux Schooner, which (acc. to the West Marine site) is for above the waterline only. Is that in reference to boats which sit in the water and therefore irrelevant to my canoe, which will spend the vast majority of its life dry?
The interlux should be OK
The waterline comment refers to permanent immersion.
I would avoid acetone as it is an unpleasant chemical & can be injurous to the health.
Wet sand the substrate with wet & dry paper then varnish. The grade of wet & dry depends on the condition of the substrate.
Interlux fiberglass solvent wash??
Is this useful or just overkill for my canoe project, or only useful for marine applications, or what?
Here’s the West Marine description:
INTERLUX 202 Fiberglass Solvent Wash
Essential for use prior to painting bare fiberglass gel coats regardless of their age. A combination of several solvents, some of which evaporate slowly to hold contaminants in suspension so they can be wiped from the surface before the solvent dries.
- Removes mold release agents, wax, oil and grease.
- Also effective for paint brush cleanup.
That would work but follow
The safety instructions as this product still contains hazardous materials.
Acetone Is Used…
…to remove any waxy substance - it’s often used to clean off epoxy amine blush between costs of epoxy. It won’t remove old varnish, but any varnish that’s solidly attached can just remain. A good sanding will roughen it enough for the new varnish to adhere well, and the edges can be feathered in…
How long it lasts depends on a number of factors - how well the surface is prepared, how good the varnish is, how well it is applied, how many coats, how much sun it gets and how the canoe is stored. I usually get two seasons from the varnish I use on my kayak’s bright-finished deck.
Wet sand it with fine sandpaper ,
like 220 before using Spar Urethane.Any gloss you want. A friend and I did her boat and it looked great.
INNTERLUX 202 Fiberglass Solvent Wash
Is a truly nasty chemical and very well may dissolve the polyester resin.
It instantly melts both vinyl and latex gloves, plastic and Styrofoam cups and other plastic stuff.
It might be safe for polyester resin, but I would NOT risk it.
Sand, wash, sand, ammonia wash, dish detergent wash, varnish.
I told the sad tale of having to remove the old fiberglass from my boat to explain why I painted the bottom. I did not get the impression your boat needed to have the glass removed.
If you sand the bottom of your canoe, then varnish with four to five coats, you should have a great finish from the standpoint of protection and satisfying gloss. All the work to make the canoe deserves nothing less.
I do a quick wipe with laquer thinner after sanding, but immediately before varnishing. As I leave the garage after varnishing, I close the door slowly and I don’t turn off the overhead (string pull) lights until the varnish is pretty dry. Any opening or closing of the door is gentle to prevent the stirring up of dust. There is always some dust in the finish, but it’s the real world. I want the best job I can get without having to rent a spray booth or go to extremes.
My boats sit in the Southern Calif. sun pretty much all the time and that’s how I found out the cheap varnish is too expensive. The good stuff lasts between one and two years. Friends have a canoe I made for them 9 or 10 years ago. They keep in indoors and it still looks like new.
Sad thing is that they took it on vacation and hit a rock hard enough to go through the first layer of glass and into the wood. You can’t even tell where the repair is after I fixed it. It freaked them out so much to damage it that they bought a Kevlar canoe and now all my work doesn’t see much use. Boo Hoo. And they are paddling in a less attractive canoe.
Beauty, man. Beauty. Go for the beauty.
It ain’t a piano
1. Dewax, sand, varnish, sand, varnish, repeat.
2. Use high quality marine spar varnish, scuffing between coats.
3. Briefly admire your work as it dries.
4. Paddle it and get a few scratches on it. It ain’t a piano.
No, it’s a hell of a lot more fun
than a piano, and a lot easier to transport.
Don’t get me wrong, I’m not looking to make a wall-mounted showpiece out of this boat. I just want it to look good like it should. Then I’ll beat it up again, fix it again, beat it, fix it, beat it… In 25 more years my daughters can take over the process.
Thanks again for all the advice, and please keep it coming if there’s something else I should be thinking about.
All the solvents mentioned on this
Board are nasty if not handled correctly. Misuse can lead at best to contact dermatitis, at worst cancer !!
This product would not attack cured gel coat 20 years old.
It will attack polystyrene cups & certain types of glove.