Carpentry and Woodworking - Spar Varnish
Doityourself.com community forum was created to provide answers to all questions related to home improvement and home repair. Doityourself community can help you find information about how-to topics on small fixes to large remodeling projects. With comprehensive how-to content and expertly moderated community forums DoItYourself.com makes it easy to tackle even the most complex home improvement projects.View Full Version : Spar Varnish
PJ57
06-13-03, 01:33 PM
I'm thinking of using Spar Varnish on a picnic table I built. A couple of questions:
1) I've read that varnish is not flexible or breathable, therefore can crack with expansion/contraction and hold moisture to cause mold growth under the finish. Any thoughts on this?
2) The can reads to apply the first coat across the grain, and subsequent coats with the grain. Why the first coat across the grain?
3) I like disposable, versus dealing with mineral spirits/clean-up. Will the foam brushes be ok?
Thanks all.
1) I've read that varnish is not flexible or breathable, therefore can crack with expansion/contraction and hold moisture to cause mold growth under the finish. Any thoughts on this?
2) The can reads to apply the first coat across the grain, and subsequent coats with the grain. Why the first coat across the grain?
3) I like disposable, versus dealing with mineral spirits/clean-up. Will the foam brushes be ok?
Thanks all.
chfite
06-13-03, 02:03 PM
The best protection for wood is paint.
Varnish does have its shortcomings. But I don't think it is all that bad. The sun and rain will eventually destroy any finish.
Apply across the grain to be sure to fill everything, pores, cracks, end grain, and such. Many apply a thinned first coat for this very purpose.
They make cheap, disposable china bristle brushes, too. Get them at the box store. I think it would be easier to work the initial coat into the wood with a bristle brush. After that, foam would be ok.
Hope this helps.
Varnish does have its shortcomings. But I don't think it is all that bad. The sun and rain will eventually destroy any finish.
Apply across the grain to be sure to fill everything, pores, cracks, end grain, and such. Many apply a thinned first coat for this very purpose.
They make cheap, disposable china bristle brushes, too. Get them at the box store. I think it would be easier to work the initial coat into the wood with a bristle brush. After that, foam would be ok.
Hope this helps.
fewalt
06-16-03, 04:22 AM
PJ57,
You're partly correct on the varnish expansion and flexibility issue.
Marine spar varnish has slightly different qualities in that is stays more flexible and can expand/contract in the weather. (Actually, spar never cures completely).
BUT, I suggest not using it if the table is left outside in the rain and sun. By next spring it will already be chipping and peeling.
This tidbit comes from experience!
Go with a good oil stain with some uv protection.
fred
You're partly correct on the varnish expansion and flexibility issue.
Marine spar varnish has slightly different qualities in that is stays more flexible and can expand/contract in the weather. (Actually, spar never cures completely).
BUT, I suggest not using it if the table is left outside in the rain and sun. By next spring it will already be chipping and peeling.
This tidbit comes from experience!
Go with a good oil stain with some uv protection.
fred