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I ahve been using Z-Poxy for quite some time and I always plan on 3 coats to get all of the pores filled and everything leveled. I wont go into how I do this as it has been stated above.

Here is something that I noticed in the last week that I found interesting:

After application, I had one area where I needed to fill a low spot in the wood. I had no problems spreading out the z-poxy with the squeegee, but noticed that after a few minutes the perectly spread low spot had massed into a Bead. The only way I can describe what happened is like this: If you took an oily piece of wood and spread some water over it with a squeegee (or squeegeed water off of a windshield), the water will want to bead back up after it has been spread out. This is what I experienced with the z-poxy. It formed a "bead" in the center of the low spot and wasnt smooth any more. Has anyone else experienced this phenomenon?

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Reguards,

Ken H

Todd,

I only dilute the epoxy for the final coat and only if I happened to sand through the epoxy to the wood on previous coats. If you can apply the epoxy, fill the pores and level everything without going through the layers to the wood, there is no need to thin the epoxy and apply more. The thinned epoxy is only to eliminate the diffeence of color where you sanded through to the wood.
There is also the technique of using epxoy to fill the pores and then sanding back to bare wood leaving only the pores filled with epoxy. This is a different technique.

Also, usually at least two full strength coats are needed to completely fill the pores.

Ken,

I haven't experienced this but I have noticed that if you use epoxy to level a low spot and then apply a finish over this area, you can get ripples in the final product. The epoxy is generally softer than the top coat (depending on the type of product you apply for the topcoat.) When buffing to a high gloss and even over time with movement of the wood, you can get a rippling effect.

Ken-
That's an interesting observation.
I haven't seen this exact thing, but when epoxy cures some 'surprises' can happen. As you know:Epoxy releases heat as the curing reaction proceeds. Where epoxy is thick, it cures faster (you can get it smoking in the mixing cup) because the heat cannot dissipate into the air quickly. Heating also makes the viscosity drop so you can get sags and runs developing, right beside 'lumps' on non-horizontal surfaces. This can be lots of 'fun' when you are learning how to use epoxy mixtures for fairing boat hulls, for example.

I'm curious to know what you figure out on this one!

Cheers
John

If using epoxy to fill a low spot you would have to have the all perimeters of the low spot all at the same level or the epoxy will attempt to sag back to lowest possible level. While epoxy is higher viscosity than water, until it has cured to firm it will seek its lowest possible level even as it is starting to thicken on the outer surface. As the chemical reaction takes place it will thicken in different locations sooner than others causing the rate of flow to vary as it seeks it’s level. The epoxy not exposed to atmosphere will thicken slower and will keep flowing to it's lowest possible location under the outer skim. This is the cause of the bead or ripple you all speak of. I can also tell you that low spot will have a different appearance under finish that the rest of the surface. Depending on the wood and the depth of the valley being leveled it may be very noticeable or just slightly noticeable.

Good point. I tried to 'drop fill' a ding in a partially-finished top with CA and then continue with FP- it looked terrible . Live and learn......

John

Thanks, Ken, Robbie, John, and Michael, for continuing to share your experiences on this topic.

Since we've sidetracked a bit into the issue of "drop-filling", I'll share this: following Sergei de Jonge's instructions, I filled a divot in an unfinished spruce top with shellac thickened to a honey consistency (by letting a small amount partially evaporate in a bottle cap). After sanding back and FPing the top, the divot was 100% invisible. Some months later, the shellac fill had shrunk back a bit*, and I repeated the thickened shellac fill, touched up the FP, and it has remained perfectly invisible since then.

*It took a very careful look under reflecting light to see that it had shrunk back at all. Most people wold never have noticed it. I'm a perfectionist.

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Todd Rose
Ithaca, NY

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