strip canoe refinishing and repair of major scratches

[paddlingredrock]

Hello, I am new here and have some questions about what some may call routine maintenance on a strip canoe. In 1981, I built a strip canoe out of redwood with my father. He passed away in 2004, so the boat has a lot of sentimental value to me. From about 81 through 2002 I used the boat extensively and it has it's share of scratches and scrapes. During the time I was using it a lot i performed routine maintenance with sanding adding coats of spar varnish. Some of the scratches were deep and into the rosin, but not the cloth, so whenever I would sand these scratches would never come out as I never sanded too far into the rosin coat. I have one very major scratch that is down into the fiberglass cloth I believe. It would never clear up after applying varnish. It is about 1/2" to 3/4" width and about 5' long. It happened when I hit something metal in the bottom of a river. At any rate I am ready to make a full assult on the canoe and sand completely down and I guess you would call it a restoration and after I am finished I want the bottom of the boat to look near new if possible and get rid of all the deep scratches and especially that major one.

I am pretty sure we used 6 oz. cloth with two layers on the bottom. Used regular fiberglass rosin and hardner as we couldn't afford the new epoxy's on the market.

I think we put 3-5 layer strips on the bow and stern tip. Those areas are becoming cloudy, but I cannot tell if they are separating from the wood (I don't think they are separating from the wood, just becoming cloudy)

I did punture the boat once in very cold weather. The puncture went through the outside of the boat, through the wood and pushed the inner fiberglass layer off the wood. When it happened I patched the cloth on the outside (puncture) and it looks great. Really can't even tell where it happened. But on the inside where the cloth separated from the wood, I drilled a small hole and injected some rosin/hardner in the small area that was separated (about 6" long by 4" width) using a syringe. The process went well but the rosin only sealed the separation in the center 1/2 of the blemish, so now the cloth is still separated from the wood around the exterior of where it separated. This episode happened about 15 years ago.

Question 1: How would repair this major scrape in the bottom that is into the cloth and looks white?

Question 2: What would you recommend for repairing the inside the boat issue where the cloth has separated from the wood in a small area? Cut that small section of fiberglass out and replace with a patch over the entire damaged area, or just keep drilling multiple holes and trying to inject more rosin in the dead air space?

Question 3: What can I do with the bow and stern stems where the coating is yellowing/opaque?

I will probably have many more questions but this is a long enough post for now. I really would appreciate any of your comments and recommendations! Thank you very much.

 

[pklonowski]

Since you didn't use epoxy originally, it's probably polyester resin? Probably the best thing to do is use a heat gun to VERY GENTLY AND PATIENTLY warm up small areas until the resin softens, then pry under it with a putty knife. I ground the corners of the putty knife down to rounded edges, to prevent major sharp gouges in thee wood. Be very patient, but don't scorch it. Keep a bucket of water with rags in it handy, in case it starts smoldering... or burning.

This is NOT a pleasant job. It will take a considerable amount of time, effort, and patience, but since you didn't use epoxy, it might come off easier. I believe it will still have an unpleasant odor, so ventilation is a really good idea. Once you have all the glass cloth off, you'll have plenty of sanding to do, which will need to be done carefully, as the remaining resin will be much harder than any exposed wood areas. At that point, you're back to where you were just before you first glassed it... so glass as usual.

For the inside, without seeing the spot, I'll guess it's best to sand out the entire pocketed area, and put on a patch that overlaps the "good" areas of glass by 2". Resin as you wood any new glass.

For the stems, are these inside or outside stems? Either way, stripping whatever finish is on them & re-finishing is probably the best bet. Outside stems will be easier than inside ones... especially since the inside ones probably got 'glassed over?

I'm sure others will chime in with more & better advice -- my experience is far more limited than several others on this forum. Hopefully this will get you started. Also note that we like pictures of canoes -- from "needs a little work," to "in restoration," to "Done!" and especially "RE-LAUNCHED!" Don't hesitate to ask, and by all means, keep us posted!

 

[paddlingredrock]

hello pklonowski... are you then recommending that I strip all the fiberglass off the outside of the boat and re-glass, rather than trying to repair that bad gouge/scratch into the cloth? Just wondering as the rest of the boat is in pretty good shape. I will try to post some pictures of the issues later this week.

Were there other types of resins available in 1981 that we may have used? My dad believed pretty strongly in using oil based, spar varnish, rather than any type of poly products. Would a poly based fiberglass resin have any incompatibilities with regular spar varnish? I don't think he would have used a poly based resin unless it was a tried and true and widespread use product, and fully compatible with regular spar varnish. He also put a lot of emphasis on using woods that were fairly weather resistant and I think he would have used chemically based products that provide for expansion/contraction and uv protection if possible.

 

[paddlingredrock]

Its the outside stems... we have bulkheads built on the inside..

 

[pklonowski]

You could do one long patch on the bad gouge. What I found when I did that, though, was I ended up with patches over patches, that overlapped patches... I wasn't very gentle with this boat, until I cracked it up badly, and had to strip off almost all of the exterior. It was not fun...

But I don't know how well the new epoxy resins will stick to the older resin, if it's not epoxy. Others here would know this better; hopefully they'll chime in. Since you indicated you didn't use epoxy when it was originally built I assumed it would be polyester.

For the outside stems, if they're just varnished, any furniture stripper should work to get the old material off. Then you just have to sand lightly, & re-varnish.

 

[paddlingredrock]

I can appreciate not wanted to patch over patches... my approach to this project is to fix everything right.. i had been using the approach you described for years as I didn't want down time and needed to back on the water.. now i am going to take my time and do it very thorough.. the rest of the canoe is in great shape over 90% of the boat, just needing sanding and varnishing, so I am apprehensive about stripping it all off. I will take some pics later this week and post, barring the 8-10" of snow doesn't put me behind on other things.. i am real interested in trying a major repair on that linear gouge into the cloth?

 

[pklonowski]

The long gouge is most likely going to need to be cut out (sanded out... whatever works), and patched. Pictures would help.