Per another thread, I wrote a question to West System about oak and epoxy and what can be done for them to just "get along". In summary, it sounds like the best you can do is to sand with fairly course sand paper (60 or 80 grit was recommended) and apply the epoxy as normal and it should work out OK. The only problem was that I guess I confused the person who wrote back because I asked about the 207 hardener which is used for table tops (as a woodworker I am interested in using it to refinish my dining room table) but I also asked about the properties when used in making FG and Epoxy layups as in strip kayaks. There's probably not much difference, but there is a possibility that it does change things. Below I have included the complete exchange.

I only edited out my home address and email address from the form that I filled out to submit my question. Everything else is intact.

Paul

*********My original email to WS:

referring_form: tech support request

Name: Paul Probus

Questions_Comments: Dear Sir or Madam,

I am writing with a question regarding Epoxy products and Oak. I am
an
amateur woodworker and kayak builder. I saw a question on the internet
in
regard to kayak building using oak and how well epoxy adheres to it.
The
responses were mostly that the oak needed to be treated prior to using
epoxy over oak because oak neutralizes epoxy resins. While I had not
planned on using oak in kayak building, I do use it in my wood working
and
was thinking of refinishing my dining room table, made of solid oak,
using
your 105 resin and 207 hardener (carried by Woodcraft in a kit form)
because I am disappointed in how badly the polyurethane held up. Can
I
use this product on oak table tops? After sanding off the
polyurethane,
how would I prepare the surface for this finish combination? At some
point I might use oak accents in my kayaks, do I have to do any kind
of
special prep work prior to epoxy-fiberglass layups using the typical
105
resin/206 hardener (or using any of the other hardeners)?

I understand that you will probably only be able to provide answers
that
apply to your own products. Since the local boating supply store
carries
West System epoxy products, I only need answers based on your
products.

Thank you for your time,
Paul Probus
=============================
*****************Reply from WS:

Dear Paul,

Bonding to Oak is problematic, but these problems can be addressed
particularly in coating applications. I suggest you do a little
experimenting on a scrap piece before diving into your table.

The structural issues with Oak won't apply to the table except as it
regards dimensional stability. Oak can and does move and twist quite a
bit more than other woods if it has a relatively high moisture content.
This may not apply to your table since it isn't fresh wood and it has
been indoors it's probably pretty dry, but you should determine this
before starting to work. Also, the epoxy will change the color of the
wood, even beyond the change from the amber cast of the 105/207 system.
We don't know why, but this is another good reason to do a test piece
first. Some folks don't like the appearance of epoxy coated Oak. As for
pre-treating, we have tried treating the Oak with a sodium hydroxide
solution to neutralize the tannic acid and measured the adhesion
against
untreated wood and did not find a difference. This isn't to say
conclusively it doesn't matter because we didn't know the acidic pH of
the wood or the basic pH of the hydroxide solution, still the treatment
didn't help adhesion.

To maximize the adhesion, sand the wood roughly in the direction of the
grain with 60 - 80 grit paper and use no solvents or tack cloths to
remove sanding dust. Vacuum and wipe with a damp paper towel. To
address
the dimensional stability, if you do decide to coat the table, I
recommend you encapsulate the table top and bottom and sides. This
insures any movement of moisture in and out happens at an equal rate
and
so stops twisting and cupping due to the relative humidity.

If you have any more questions please feel free to call or write.

Regards,

Bruce Niederer
Technical Advisor