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Z-poxy is not drying
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Author:  bcombs510 [ Wed Jan 06, 2016 7:43 pm ]
Post subject:  Z-poxy is not drying
Hello,

I put two coats of z-poxy on a zebra wood build following the YouTube videos from Todd Stock. The first two coats went on great but this last coat is not drying. It's been 36 hours.

I didn't thin the z-poxy as I saw in some posts from the past where drying was an issue.

I mixed with a digital scale and let it set up after mixing for about a minute. I also saw that a bad mix could cause this.

The one thing that is different from the first two coats is it got cold here and my shop is in the basement. It was 62 degrees in the spray both area I concocted. [SMILING FACE WITH SMILING EYES]

I have since moved the body upstairs for 8 hours and it still isn't setting up.

What's the best way to pull the epoxy back off while it's wet? Would it be Denatured alcohol on a rag?

Thanks!
Brad


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Author:  StevenWheeler [ Wed Jan 06, 2016 7:57 pm ]
Post subject:  Re: Z-poxy is not drying
That's what I would do. Might need something with a bit more bite than a rag. Burlap would be good, or "Scotchbrite" type synthetic wool. If using steel or synthetic wool, don't get too aggressive.

Steve
Author:  johnparchem [ Wed Jan 06, 2016 8:14 pm ]
Post subject:  Re: Z-poxy is not drying
I would knock off the corners of a razor blade and use it scrape off the soft epoxy.
Author:  kencierp [ Wed Jan 06, 2016 8:45 pm ]
Post subject:  Re: Z-poxy is not drying
Zpoxy is supposed to be mixed equal parts by volume -- the resin is heavier than the hardener, if too much hardener is used the product will remain gummy. Also it is very temperature sensitive 69 degrees is the minimum. But I suspect the mix ratio was off. $.02
Author:  bcombs510 [ Wed Jan 06, 2016 9:08 pm ]
Post subject:  Re: Z-poxy is not drying
Excellent, that is probably it. I was using a scale not a measuring cup. Thanks for the tip! I'll clear this off and try it again.


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Author:  Mike OMelia [ Wed Jan 06, 2016 11:16 pm ]
Post subject:  Re: Z-poxy is not drying
Z-poxy is very forgiving on mix ratio. I have always done it by eye. Volumetricaly, never had a single issue. Even with thinning with DNA. Something else is going on. Humidity? Cold temps? Product age?

Seems to me a volume test will answer this.
Author:  Hesh [ Thu Jan 07, 2016 7:38 am ]
Post subject:  Re: Z-poxy is not drying
Brad forgive the following question, it's not directed at you or anyone else specifically. It's just something that was the root cause of some other Z-Poxy issues back in the day on the forum.

You're sure that you are using Z-Poxy "finishing resin" and not any of the various flavors of "Z-Poxy ep*xy" right?

If so I think that Ken may have nailed it with the temps in your shop being too cool for the stuff to properly harden during it's window of chemical reaction with the hardener.
Author:  PeterF [ Thu Jan 07, 2016 8:55 am ]
Post subject:  Re: Z-poxy is not drying
I've had epoxy take days to cure before and it's always been because it was too cold. It cures with an exothermic reaction, and when pore filling, it gets spread very thin, allowing the heat to escape quickly. Heat it up to 25°C for a while and it should be fine

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Author:  bcombs510 [ Thu Jan 07, 2016 1:35 pm ]
Post subject:  Re: Z-poxy is not drying
Hesh wrote:
Brad forgive the following question, it's not directed at you or anyone else specifically. It's just something that was the root cause of some other Z-Poxy issues back in the day on the forum.

You're sure that you are using Z-Poxy "finishing resin" and not any of the various flavors of "Z-Poxy ep*xy" right?

If so I think that Ken may have nailed it with the temps in your shop being too cool for the stuff to properly harden during it's window of chemical reaction with the hardener.


Thanks, Hesh. I'm using this: http://www.amazon.com/gp/product/B0006O ... ge_o00_s00

(Here's to hoping it's the right thing!!)

FWIW, I took a scotchbrite backed sponge this morning and put a little denatured alcohol on it. I lightly scrubbed the back and sides and squeegeed off the liquid. It seems to be leveled back out now and the tacky epoxy is off. I'll let it sit a few more hours before trying another thin coat of the z-poxy. Provided you don't come back telling me I bought the wrong thing. :)

Thanks!
Brad
Author:  Hesh [ Thu Jan 07, 2016 2:22 pm ]
Post subject:  Re: Z-poxy is not drying
bcombs510 wrote:
Hesh wrote:
Brad forgive the following question, it's not directed at you or anyone else specifically. It's just something that was the root cause of some other Z-Poxy issues back in the day on the forum.

You're sure that you are using Z-Poxy "finishing resin" and not any of the various flavors of "Z-Poxy ep*xy" right?

If so I think that Ken may have nailed it with the temps in your shop being too cool for the stuff to properly harden during it's window of chemical reaction with the hardener.


Thanks, Hesh. I'm using this: http://www.amazon.com/gp/product/B0006O ... ge_o00_s00

(Here's to hoping it's the right thing!!)

FWIW, I took a scotchbrite backed sponge this morning and put a little denatured alcohol on it. I lightly scrubbed the back and sides and squeegeed off the liquid. It seems to be leveled back out now and the tacky epoxy is off. I'll let it sit a few more hours before trying another thin coat of the z-poxy. Provided you don't come back telling me I bought the wrong thing. :)

Thanks!
Brad


Perfect - that is the right thing! :) Didn't mean to alarm you my friend.
Author:  Clay S. [ Thu Jan 07, 2016 9:07 pm ]
Post subject:  Re: Z-poxy is not drying
"I've had epoxy take days to cure before and it's always been because it was too cold. It cures with an exothermic reaction, and when pore filling, it gets spread very thin, allowing the heat to escape quickly. Heat it up to 25°C for a while and it should be fine"

Ditto
Author:  Mike OMelia [ Thu Jan 07, 2016 9:45 pm ]
Post subject:  Re: Z-poxy is not drying
That is the right product. Got an update for us? Did you do a spot test? Eyeball a small amount of each on a paper plate, mix, and let cure
Author:  bcombs510 [ Fri Jan 08, 2016 9:34 am ]
Post subject:  Re: Z-poxy is not drying
Mike O'Melia wrote:
That is the right product. Got an update for us? Did you do a spot test? Eyeball a small amount of each on a paper plate, mix, and let cure


Thanks, Mike.

I used a scotchbrite backed sponge with some denatured alcohol and removed the tacky epoxy. Let it sit for a day then put another thin coat on it. This is now considered the second coat I guess. :)

The only problem is, as you can see in the pics, I'm hanging in the upstairs bathroom now because my shop is in the basement and apparently stays too cool. I don't want to try to heat the shop 24x7 so this will have to do until spring!

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Author:  bcombs510 [ Fri Jan 08, 2016 9:38 am ]
Post subject:  Re: Z-poxy is not drying
Mike, a question for you. Between coats 2 & 3, are you using just a razor to clean up and then a light scotchbrite? I think that is what Todd said in the video though I need to watch again. I think after coat one I got pretty close back to wood, then had the mishap with the "first" second coat. Now I'm back to a proper setup and a second coat. So what to do in between this one and coat 3, which is supposed to be really thin I believe.

Thanks!
Brad
Author:  Mike OMelia [ Fri Jan 08, 2016 1:50 pm ]
Post subject:  Re: Z-poxy is not drying
Yes. I even use a little 400 grit for tougher spots. BTW, are those pics of wet coats? If so, you possess great skill at leveling. What tools are you using? BTW, I would have taped off the front to avoid any epoxy getting on the top. Walmart sells this large roll of white freezer wrap. One side is plastic coated. I lay dry guitar on wrap, trace outline, then under cut by an inch, attach with 3M Blue Sensitive Surface tape, razor off the edges. Plastic side is exposed side.

I still struggle with getting a glassy application. But I saw something in your picture I had not thought about. The wooden handle. That should help!!

PS: You must have an understanding wife!
Author:  bcombs510 [ Fri Jan 08, 2016 2:18 pm ]
Post subject:  Re: Z-poxy is not drying
Mike O'Melia wrote:
BTW, are those pics of wet coats?


It was put on about an hour or two before the pics.

Mike O'Melia wrote:
What tools are you using? BTW, I would have taped off the front to avoid any epoxy getting on the top. Walmart sells this large roll of white freezer wrap. One side is plastic coated. I lay dry guitar on wrap, trace outline, then under cut by an inch, attach with 3M Blue Sensitive Surface tape, razor off the edges. Plastic side is exposed side.


Yes, good idea. I wish I had covered the top as I did get some on there when I was doing the Denatured Alcohol removal of the botched 2nd coat. I'm using the Etorre squeegee. I cut it in half as you had suggested in another thread. Works great. One thing that is helping to smooth it out, for me at least, is that when I'm ready to put some pressure on and take off the excess I'm wiping the squeegee on a rag between each pass that is damp with denatured alcohol. Maybe a bit of the alcohol is hanging around on the squeegee?

Mike O'Melia wrote:
PS: You must have an understanding wife!


Indeed.

BTW: About the wood handle. that does help. I've been clamping it into a vise so that I can apply adequate pressure when taking the excess off.
Author:  Mike OMelia [ Fri Jan 08, 2016 11:11 pm ]
Post subject:  Re: Z-poxy is not drying
I do the same thing, cleaning the squeegee as I go. I think ur use of the handle gives u the control for wiping the epoxy I have been looking for, especially on the sides. I think you are going to be extremely pleased with how this turns out. Just use 400 and scotch brite to level back. Light touch.
Author:  Goat Rock Ukulele [ Fri Jan 08, 2016 11:45 pm ]
Post subject:  Re: Z-poxy is not drying
If your zpoxy is not fresh you can start to have problems around the edges. In your case the edge was it being a little cold. As others have said don't bother weighing it use volume. I just use a timed squeeze out of the bottles an have never had a problem as long as it is fresh. After a year or so it does not harden as well. Your zpoxy will still probably go off ok if you get the temperature up for a couple days. But it is a much slower process if it doesn't harden on the initial cure.
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