Repairing cap rail varnish

[chrisjs]

I have many coats of Epifanes varnish on my teak cap rail. In a few areas around scarfs and fittings there has been some water intrusion that has caused discoloration under the varnish, though the surface integrity appears decent. I also have a couple of dings where minor events have chipped out small section of varnish down to bare wood.
My question is whether it is practical to remove the varnish down to bare wood just in the affected areas, then to fill the voids with clear epoxy to bring them level with the remaining varnish, before over coating the whole rail with a couple of new coats of Epifanes. It would seem like using the thicker epoxy to raise up the level would simplify build back before re-varnishing. I would appreciate input and recommendations regarding the right type of epoxy etc.

[Pblais]

I wouldn't use any epoxy on this boat to fill anything wood. If later down the road you want to use an epoxy based clear coat it is another matter. You can stick with Epifanes if you like but once there is water intrusion is has to come off.

You could sand everything back to bare wood and build up to patch it. The patches may not look so good next to the unpatched but if the rest is not effected by water intrusion it will just look "patchy". Once you lay enough coats it does not look as nice in any case. Everything that goes on eventually has a day when it all has to come off.

Epoxy in the scarf joints probably won't work in any case and it will ail be a nightmare to get off when it does fail again. The joints expand and contract from moisture and heat. They won't stick together from an epoxy filler. Getting it back to bare wood and refinished will at least keep the water out and maybe solve the problem until water finds it's way in again. Sanding it back helps a lot. The best you can do is keep the water out with a good finish applied over clean wood!

[foolishsailor]

Best to use a cabinet scraper to remove the loose varnish and then taper the good varnish around the edges with sandpaper and a sanding block. You can the use oxalic acid, google it available anywhere, to take the water stains from the wood. After that you can tape around the existing varnish about where you think it is still full thickness outside the taper you sanded and start building up the varnish. Once done, pull the tape and sand flush.

Sounds like a lot of workout but isn't, especially if you do all the spots at once. E best way to deal with varnish is to not let it go for long. A small bottle with a brush pushed through the lid and sealed is great to have around. As soon as a bit of varnish cracks or peels you can pull it off with a cabinet scraper, open your varnish jar and brush and coat it and close e jar back up with the brush. Really extends the life of external varnish and minimises the big year end varnish jobs.

Edit: oh yea about the epoxy, never ever use epoxy as a void filler for dents etc. if you absolutely must use it it is acceptable to use for gaps in joints etc. just remember that epoxy and wood share very different material characteristics. One is rigid and brittle the other flexible and soft. Where the two meet there will always be long term problems. Also note that epoxy does not like uv so make sure there are plenty of layers of varnish or whatever on top of epoxy to ensure it is uv protected

[chrisjs]

Thanks for the help and advice regarding epoxy. I am off to buy a cabinet scraper for the tool kit!! I guess there are no real short cuts!!
Chris

[foolishsailor]

If you learn how to sharpen your cabinet scraper, again google it, you will find it is itself a shortcut.

As a carpenter and past wooden boat builder can i suggest your questions regarding varnsh and wood would be better answered on this forum

http://forum.woodenboat.com/

The depth of knowledge is unreal. Just be careful there are two really hot topics....use of epoxy and varnish so your question is like a thermonuclear bomb.

[foolishsailor]

By the way a great quick primer on varnish maintenance can be fond here

http://www.defender.com/html/varnish-repair.html

[Cheechako]

Originally Posted by Pblais

I wouldn't use any epoxy on this boat to fill anything wood. If later down the road you want to use an epoxy based clear coat it is another matter. You can stick with Epifanes if you like but once there is water intrusion is has to come off.

You could sand everything back to bare wood and build up to patch it. The patches may not look so good next to the unpatched but if the rest is not effected by water intrusion it will just look "patchy". Once you lay enough coats it does not look as nice in any case. Everything that goes on eventually has a day when it all has to come off.

Epoxy in the scarf joints probably won't work in any case and it will ail be a nightmare to get off when it does fail again. The joints expand and contract from moisture and heat. They won't stick together from an epoxy filler. Getting it back to bare wood and refinished will at least keep the water out and maybe solve the problem until water finds it's way in again. Sanding it back helps a lot. The best you can do is keep the water out with a good finish applied over clean wood!

agree totally. No epoxy. if you want the color to be the same you have to strip it all. Just stripping the bad area will result in discolored /non matching finish.

[slowshoes]

Agree with the no epoxy comments. There's no need to strip all the varnish off because of a small scrape or area of lifting - you'll be forever striping and varnishing and actually sailing will be a distant memory.

I have an acre of varnish on my boat and have had good results doing exactly as foolishsailor suggests. If the varnish is very old, you may be better off just accepting the inevitable and stripping it all off and starting over.

Here's a good book on all things varnish:

[foolishsailor]

Originally Posted by slowshoes

Agree with the no epoxy comments. There's no need to strip all the varnish off because of a small scrape or area of lifting - you'll be forever striping and varnishing and actually sailing will be a distant memory.

I have an acre of varnish on my boat and have had good results doing exactly as foolishsailor suggests. If the varnish is very old, you may be better off just accepting the inevitable and stripping it all off and starting over.

Here's a good book on all things varnish:

Brilliant book. No matter how skilled all varnish "specialists" can take from this book.

Another item to note....if you are using epoky on bare wood to fill joints - if you get epoxy on bare wood and then varnish it the wood wont take up the varnish and it will intead sit "on top" of the wood and therefore will be a different color. A sad and common effect on amateur boats is near all wood joints the glue and or epoxy was not carefully applied and near the joint you get light spots where the epoxy or glue filled the wood prior to varnish...

for epoxy can be avoided by using tape and by not applying huge amounts of epoxy to glue jobs. for glue can be avioded by wetting the wood around the joint (not the joint itself) and having a wet cloth and water in hand after the joint is glued/clamped and throughly wiping up the glue over and over again with a clean wet cloth.

This topic like many involving wood, varnish, glue and epoxy is covered extensively on the forum i recommended...it is a LARGE set of topics....