Stain finishes and epoxy

[CenCalCapri]

I have a finishing question and hope someone has some experience to share. I plan to make a Bolger design (plywood, of course), and would like to finish it wood grain as much as I can, sanding and filling, then stain it dark as if it were a desk or bookshelf, then seal it with epoxy and glass cloth.

Will the oil stain ruin the bonding of the epoxy? I experimented with glass and resin over stain and the results were poor, the delamination coming quickly after water contact. Would stain and epoxy be better? Or should I just epoxy and paint?

[Todd Bradshaw]

If you want to epoxy-coat over stain, use water or alcohol-based stains. not oil-based stain. The oiled surface is not a very good base for epoxy and will reduce its ability to bond and seal properly.


WEST 105/207 epoxy over alcohol-based stain (don't forget the UV varnish on top to protect the epoxy)
http://webpages.charter.net/tbradshaw/star.jpg

[David G]

The products Todd is referring to are the correct ones to use. And, as his example illustrates, they can be quite gorgeous. In the industry they are called dye-stains... or simply analine dyes. The water-soluble and alcohol-soluble versions are quite similar, but the water-based ones are significantly more resistant to fading from UV exposure. They come in powders which you mix with the water or alcohol, or pre-mixed. One major supplier is Behlen:

http://www.behlen.co.uk/Merchant2/merchant.mvc?Screen=CTGY&Category_Code=DYEST

Reading between the lines of your post, I'm gonna guess you're a relatively inexperienced boatbuilder/woodworker? I'll warn you that dye-stains are not commonly thought of as a product for beginning wood finishers. If you're willing to educate yourself, and possess a meticulous, methodical nature, I think you could consider this route... but most beginners will find it frustrating. Definitely plan on spraying the stain, as brushing/rolling a large surface is quite tricky without leaving it blotchy and/or streaky.

What Bolger boat are you building? In most cases, I suggest painting most of the boat, instead of varnishing. This is especially true for less experienced folks.