Need some first time advice.

[mstermer]

This is my first time posting, and really my first time doing anything like this (canoe restoration wise). I recently got a 14' 1986 Huron canoe from Great Canadian. Overall the boat is in great shape (although from reading around I hear they might not be the greatest construction, but there's no real problems with the boat). One thing I do need to fix on it is the varnish. Right now the varnish coat that goes on top of the epoxy covering the fiberglass with peeling a bit. There is no damage to the epoxy or the fiberglass. I just wish to clean off the peeling and give the boat a new coat.

Here's my questions:

Is this a good idea?
Would a light sanding down of the peeling varnish be the best method for this?
I found that the maker used McCloskey's Man o' War Marine Spar Varnish originally to coat the boat. I've read I need to know the kind of epoxy used on the boat so this doesn't react poorly to the varnish, but would this be needed if i know the original varnish?

any other advice for this newbie would be appreciated. I'm a bit of a fish out of water right now, but am trying to learn what I'm doing since I'm really interested in caring for this boat and any future wooden canoes i may get.

 

[Todd Bradshaw]

Yes, it would be a good idea to sand first, removing any varnish that is loose, smoothing out any sort of "step-down" between peeled and un-peeled varnish spots and putting some "tooth" on the remaining old varnish for better adhesion of the new layers. Epoxy is generally a fair bit harder than varnish and with reasonable care, you should be able to sand the old varnish down (or even off) without doing any serious damage to the epoxy. In some ways, removing all the varnish might be the best bet, since varnish tends to yellow over time and mixing areas with old varnish and areas where there is no remaining old varnish can tend to look a bit spotty once the new stuff is applied on top. You'll have to make that call when you get to see what it looks like. For a reasonably decent preview, you can wet down the sanded surface with a wet sponge and get a quick look at the color before the water evaporates.

There are some chemical strippers that are reasonably safe on fiberglass (and labeled as such) but others will tend to attack it, so sanding is a lot safer. A random orbit machine and 100-150 grit disks would be my choice, though you could sand it by hand if needed (probably 220 grit, and not much reson to go any finer as it will start to diminish new varnish adhesion).

Nearly any spar or urethane varnish will work safely on just about any properly prepared epoxy, polyester or vinylester resin, so I wouldn't worry much about what brands of resin or varnish they used. Reactions tend to be quite rare and generally involve some of the specialty varnishes that use strong solvents or catalyzing agents, not the regular boat stuff. It's also not a bad idea to avoid solvent contamination of the sanded surface. Some folks wipe boats down with every damned solvent they can find in their paint cabinet and this is both unneeded, and can lead to adhesion problems. A good washing of the sanded resin surface with plain water and a scotchbrite pad is all the "cleaning" that the epoxy generally needs and doesn't leave any stuff on the surface that you will later regret. Follow this with two or three coats of a good UV-filtered marine exterior varnish to protect the epoxy from the sun and you should be good to go.

 

[mstermer]

Thanks so much Todd,

followed all your advice this weekend. was able to sand down the varnish in much shorter of a time than i thought by hand with 220 sandpaper and some hand discs. Gave it her first coat of varnish and was amazed how much it really brought the boat to life. Doing the second coat tomorrow most likely and should have it in the water for the first time next weekend. Thanks so much for the advice, it was extremely helpful. So thankful I was able to turn to this great site and message board when I was clueless.