Official Luthiers Forum!

I wanted to ask if the folks who use zpoxy as a pore filler, seal coat the guitar before applying the zpoxy. I have a coco bolo bound ukulele that I want to try zpoxy on and am wondering if the bindings will bleed onto the rest of the surface.Thank you for any replies.

michael keller

Yes they can bleed. Zpoxy wants to be on raw wood; it does not stick well to shellac (although shellac sticks to it). What I have done is to mix a small batch of zpoxy and then dilute it with alcohol and use a cotton rag to wipe the binding taking care not to smear the body. In an hour or two you can pore fill the rest of the body. I do this technique for the reverse as well when I have light bindings on rosewood.

_________________
http://www.Harvestmoonguitars.com

You could first seal the bindings with a coat of zpoxy. I would consider something like this:
1.) mask off sides/back/top
2.) spread a nice thick coat over the binding that hopefully penetrates the wood a tad
3.) wipe off as much as possible
4.) unmask/let dry
5.) scrape/scuff it smooth
6.) pore fill as you usually would.

wiping it down vigorously with alcohol or lacquer thinner prior to epoxy will also help prevent bleeding.

I've used oily woods like coco, both as B&S and binding, with z-poxy and System 3 but have not ever seen any bleeding caused but the epoxy. Could just be me so I suppose caution is good.

Edit: I also put epoxy on bare wood, and apply 2nd & 3rd coat as soon as the previous coat has set enough to handle. Better bond between coats that way.

_________________
Joe Beaver
Maker of Sawdust

To your first question, I apply z-poxy to the wood, no sealer coat before z-poxy. So far, I've used z-poxy on cocobolo and bloodwood binding with no bleeding. Maybe I was just lucky. One option is to use some of the left over binding you have and glue it to scrap from the sides/back wood to make a mockup of the binding-to-sides joint and then apply z-poxy as a test to see if the coco bleeds. Otherwise, sealing the binding with z-poxy as suggested above would be a good cautious approach.

_________________
Once in a while you get shown the light in the strangest of places if you look at it right - Robert Hunter

I have definitely had serious problems with cocobolo bleeding with zpoxy.

Nils, how bad where the problems and how did you fix them. I am afraid the resin will bleed into top wood and be hard to get out. The board of coco bola I am cutting into bindings is really resinous. I would never, ever try to wipe the installed bindings with ANY solvent as napth or laq thinner pulls out the resins. Allot!

michael keller
http://www.kellerguitars.com

We sand to P220, perform a good compressed air cleaning of pores, seams, etc., mask the coco bindings at the black fiber line and epoxy wipe, leaving the thinnest layer possible. Once cured, we use non-woven abrasive to tooth the surface and apply epoxy to the rest of the guitar without bleeding issues. If sanding back to wood for each coat, the same process is followed each time, but we don't, so the only extra work is the separate initial coat on bindings.

For coco body wood, we seal the purfings and bindings first as above, then apply the first coat as we usually so, which is to say a thin coat with as much removal as possible. That coat is lightly scraped and toothed, but retains a good, sealed surface for subsequent coats.

_________________
A constellation only takes shape when one maps the whole.
- Beth Brower

I wonder if people that thin their finishing resin with something like DNA have more oily wood bleeding?

_________________
Joe Beaver
Maker of Sawdust