Bar top with epoxy finish (got bubbles)

[dlcw]

Ok all you finishing experts out there, I am finishing two solid cedar slabs with West Systems epoxy using the super slow hardener to slow the curing process. When I lay on a coat of the mixture, I'm getting air bubbles.

Can any one suggest the tools/applicators and techniques they have used to apply a clear epoxy coat and not get a bunch of bubbles mucking up the finish?

Thanks!!

[garyc]

Don...
A few things to try based on a good number of these done in FL:

If no bubbles are in your mix bucket then bubbles are being released from wood. If they are in the mix, then heat mix and stir slower.

Use a thinnned down version to get the pourous (even open pore) woods like Cedar sealed. I prefer the faster drying versions, especially for this step. Use Xylol or other recommended thinner for your brand. Mix A/B thoroughly before and let sit for 10 min, then add thinner

Use a heat gun, hair dryer or small torch to bring up and eliminate the bubbles. Heat thins out the epoxy, lets the bubble rise and break.

Most that I have done were hi build with multiple coats, once sealed I used 80-120 to sand/level. If bubbles are in 1st coat, sand them out when cured.

Dont push the "full cure time" before sanding/routing

[cabnet636]

As Gary said A "Whoosh" with a torch or a Hair dryer,, do not let the torch point as epoxy will burn, nt as in massive fire but as in Ugly spot !!

[frank134]

make sure you stir and don,t shake the mix. stir slow.

[dlcw]

Thanks for the advice everyone. I have sanding to do on the first coat and will use the advice given on the second coat.

The other problem I noted was the inherent problem with all confer woods, when you sand, you get shallow divots in the soft wood between the growth rings. I'm hoping with enough coats, and sanding level between coats, this will disappear.

[dlcw]

What is the proper technique and tools needed to put down a nice smooth, no bubble, layer of epoxy?

I've sanded back down to bare wood to start over again as the bubbles were just to bad.

[Greybarn]

Which epoxy are you using?

[dlcw]

Which epoxy are you using?

"West Systems epoxy using the super slow hardener to slow the curing process."

[hespj]

What time of day did you epoxy? Or more specifically, was the wood heating up? If you epoxy coat when the temperature of the wood is rising (at a faster rate than the air around the wood) the air inside the wood expands and air can move outwards.

Assuming the wood only gets its heat conducted from the surrounding air it'll heat up slower than the air in the workshop in the morning and cool down slower in the evening, so late afternoon is sometimes said to be a good time to epoxy - the air inside the wood is contracting.

Having said that, you'll probably be okay now you've epoxied once, unless you've really taken all the epoxy off.

John

Edit. I've used an awful lot of epoxy of the last twenty years but I've never used super slow. It may be that the very long curing time is just allowing more time for bubbles to form.

[Greybarn]

Not to push any specific product but for clear finishes we have the best luck using System Three.

[twelchPTM]

make sure you are putting down a nice thin base coat, enough to soak in and seal the wood but not thick enough to host any bubbles, this will make sure nothing is seeping up from the work piece. then work in layers (not sure about the west systems but most i've tried recomend working in 16th" layers and no more then 8th"). stir slow to keep bubbles to a minimum and pour slow. then as the others have stated a little heat will pull out the bubbles

[dlcw]

Thanks everyone.

Yes, I did, unfortunately, have to take the first layer back down to bare wood. I will now have to reapply the stain, let it dry for a day then apply another "first" epoxy coat to seal the wood. I will check into a thinner for West Systems epoxy for that first coat.

I have perfectly leveled the boards and put a band of green painters tape around the edge to create a "dam" to keep the epoxy from just running over the edges onto the floor.

My big question is what is the best way to actually put the epoxy on the material and spread it around evenly and keeping bubbles out? This is where I'm struggling the most. Proper application technique - getting it to flow out evenly over the entire surface. Do I use a foam roller, a squeegee?

I apply epoxy as the last thing I do in the shop before quitting for the day. I let the shop dust settle and get sucked up into air cleaners for a couple of hours, vacuum the table tops, then apply the epoxy. It can sit over night undisturbed.

[dmidkiff]

Don I am currently doing the same thing as you, down to sanding and starting over. I am using West System but not experienced with it, or any other epoxy brand. The squeegee has been the best way for me to apply. After it is all smoothed out, I go over with a disposable brush. Looked good last night, hope it looks the same this morning.

[cabnet636]

I have done many a 60' plus bar top and one 16" deep by 48 lin feet ($125.000.00 and looked like an Aquarium when we were done )

Thin coats, thin coats thin coats,,,,, use a torch (it is the carbon dioxide) to remove bubbles, hair dryer works but torch works better,, Whoosh with torch (yes I have burned a top) to many times we want to "get it done" and go on thick,, not good,, make a little spread it make a little spread it,, thin coats,, thin coats

[dmidkiff]

Did not turn out good this morning. Did not level out like it should. Before, I thought temp. could be the problem, and applied a coat early and set in sun. It got bubbles like earlier post said. (Did this before the post.) Now I'm thinking it could be that the epoxy has been here too long. Do not remember reading about shelf life. If I torch it will it level out? If I apply another coat, will it level out? Thanks

[cabnet636]

this stuff has a shelf life !! might want to cure to quick as well (Gel)

[dlcw]

I talked to one of the guys at West Systems yesterday for about 20 minutes. He said the same thing you did James, use a torch to bring the bubbles to the surface. Also, put on a seal coat of thinned epoxy so the cedar doesn't off gas and cause bubbles. Stir the mixture SLOOOOWLY so as to keep the bubbles to a minimum. Use thin coats and the torch to work the bubbles out. Let it sit for 10 to 15 minutes and come back with the torch to get the remaining bubbles out. Going to try it tonight.

He also said to use the 207 clear hardener not the 209 super slow hardener. ****, I already bought a couple containers of the 209. 207 is a lot more expensive. :eek:

At the very least, this will be a learning project. Good thing I don't have much money in materials (other then epoxy) and labor cost should help me at least break even. :)

[Regnar]

Other than drying time I dont see what 207 would have and advantage over 209. I have used both and although 20 minutes seems like a long time it goes by really quick when you have a mistake. You can always add a heat lamp to speed up curing times.

All of them where done using 209 and the last one was just one thin coat.

[dlcw]

Russell,

According to West Systems tech support, the 207 hardener dries perfectly clear whereas the 209 dries with an amber tone. Since I've used stain to color the wood to the customers exact specifications, I would want the clear epoxy versus the amber of 209.

He said if the amber tones is acceptable, then 209 would work fine.

[dlcw]

Other than drying time I dont see what 207 would have and advantage over 209. I have used both and although 20 minutes seems like a long time it goes by really quick when you have a mistake. You can always add a heat lamp to speed up curing times.

All of them where done using 209 and the last one was just one thin coat.

Beautiful tops!!!!! I'm envious. I hope mine turn out half as good as yours.

[dlcw]

Russell,

I sent you a PM.

[dlcw]

Ok. Started all over. Applied customers Minwax oil based stain. Let it dry for 3 days. Rubbed out with white nylon pad. Vacuumed the hell out of it. Applied West Systems 105/207 epoxy combination slightly thinned with acetone using a china bristle brush with bristles cut to about 3/4" long per West Systems tech.

Results :eek: :eek:

Now what? Could it be the Minwax stain that is causing this to happen? Tell customer they can't have the stain applied or epoxy won't take?

Needless to say, I'm a little baffled now.

[billp]

I've slung a lot of epoxy over the years and NEVER had any luck with it adhering to any surface that did not have some "tooth" to it. Could be that your white nylon pad polished, rather than roughed up the surface. Could you do a small test piece of any other material, only this time lightly hit the Minwax with something like 150 grit ?
I have usualy applied the epoxy to the bare surface as a sealer /undercoat, and THEN put the final finish ( with UV filter) on TOP of the epoxy. If you put the epoxy OVER the Minwax, you'll still need to go back and topcoat over it again to protect it from sunlight...

[dlcw]

Bill,

I think the stain is the issue. I could try and rough it up by I think since it is so thin I would rub right through to bare wood defeating the purpose of the stain.

I might be at the point of telling the customer the epoxy is just not going to adhere properly to the stain.

I can use the 105/209 combination to get an amber tone to the epoxy (according to West Systems). The 109/207 is perfectly clear (according to West Systems).

I'm in luck because the bar tables will be in a basement without sun shining in.

[wberminio]

Don
I don"t have much experience with epoxy,but from what I see from your photos.
there is a reaction with the epoxy and base coat.
It is more than just bubbles.It looks similar to adding waterbase finish over an oil finish.
You may be right about the stain.Try a sample on an unstained sample and see what happens.

Erminio

[dlcw]

I've slung a lot of epoxy over the years and NEVER had any luck with it adhering to any surface that did not have some "tooth" to it. Could be that your white nylon pad polished, rather than roughed up the surface. Could you do a small test piece of any other material, only this time lightly hit the Minwax with something like 150 grit ?
I have usualy applied the epoxy to the bare surface as a sealer /undercoat, and THEN put the final finish ( with UV filter) on TOP of the epoxy. If you put the epoxy OVER the Minwax, you'll still need to go back and topcoat over it again to protect it from sunlight...

Bill,

I just tried sanding a section of the second table top with the stain to 150 grit. Definitely dulled the stain finish. The results after putting epoxy on were identical to the first process of applying it over non sanded stain. I think the epoxy does NOT like the stain. I've already informed the customer that the stain is not going to work under the epoxy but I can use a different hardener that adds an amber tone. We'll see what he says.

[Ajcoholic]

Don,
I have quite a bit of epoxy experience - maily with West systems product but others as well.

I would not recommend trying to put the epoxy over an oil based stain, and not that soon especially.

I have coated wood with epoxy, and to stain, I used NRG (analine dye dissolved in methyl alcohol) sprayed on the wood to add the colour, and the epoxy will go over that without issue as the carrier (alcohol) completely evaporates and only the dye is left.

You can also tint the epoxy lightly with universal tints (they make them for epoxies).

That being said, West systems (or any other finishing/structural epoxy) is not really the best for this purpose although it can be used. There are special bar top epoxies like "Nu-clear", etc that are specifically made to give a thick, clear finish on tops, and doesnt need any additional treatment afterwards.

The epoxy is doing exactly what a finish does, when you have silicone contamination on wood. The epoxy seems to be pooling away from the grain where the oil has soaked in.

AJC

[Regnar]

Don,

First we need you to stop experimenting on your real deal. If you have some scrap of the butcher block experiment on it.

I dont know how much luck you have but your ran out here. MinWax Oil Based Stain is a double fail with West Systems Test. It took some digging but I found it here for you..

http://www.westsystem.com/ss/epoxy-adhesion-over-stains/ .

Dont feel bad I learned the hard way as well.

[kevin]

Don use a sealer first it will also help with leveling out make shur your totally sealed the more the better

I work with it first time on concrete counter top for a customer its a bitch there is a learning curve good advice here

[gerryv]

Thanks much Russell.

[dlcw]

I would like to thank everyone for their incredible feedback and advice on this subject.

Russell, that was not a document I had seen nor had the tech at West Systems mentioned it. The Minwax stain mentioned as FAIL across the board is exactly the stuff the customer gave me. Go figure. Priceless information. THANK YOU!!!!

I've contacted the customer and they are ok with the clear cedar top with some amber tone epoxy. I am going to experiment on a small board with some NGR dye I have and see if that will give him the color he wants and lets the epoxy work correctly as per Andrew's advice. He will be stopping by tomorrow so he can see what is going on.

THANK YOU all again so much. Your experience has been priceless... :)

[dlcw]

Don,
I have quite a bit of epoxy experience - maily with West systems product but others as well.

I would not recommend trying to put the epoxy over an oil based stain, and not that soon especially.

I have coated wood with epoxy, and to stain, I used NRG (analine dye dissolved in methyl alcohol) sprayed on the wood to add the colour, and the epoxy will go over that without issue as the carrier (alcohol) completely evaporates and only the dye is left.

You can also tint the epoxy lightly with universal tints (they make them for epoxies).

That being said, West systems (or any other finishing/structural epoxy) is not really the best for this purpose although it can be used. There are special bar top epoxies like "Nu-clear", etc that are specifically made to give a thick, clear finish on tops, and doesnt need any additional treatment afterwards.

The epoxy is doing exactly what a finish does, when you have silicone contamination on wood. The epoxy seems to be pooling away from the grain where the oil has soaked in.

AJC

Andrew,

How long do you let the NGR dye dry before you apply the epoxy? I know with regular finishes (lacquer, conversion varnish, poly) I can put first coat on in about 3 hours after apply the NGR dye.

Just curious if with epoxy you need to let it dry longer.

[Ajcoholic]

Andrew,

How long do you let the NGR dye dry before you apply the epoxy? I know with regular finishes (lacquer, conversion varnish, poly) I can put first coat on in about 3 hours after apply the NGR dye.

Just curious if with epoxy you need to let it dry longer.

The methyl alcohol carrier evaporates within minutes. When I spray raw NGR I coat over it immediately (with lacquers, etc). No need to wait 3 hours.

The last job I did this on, was a few years ago - I built my wife a Kayak, and stained half the hull with dark walnut NRG - and I put it on with a rag not spraying (to get a very deep colour) and glassed the hull shortly afterwards. Even if there were any remnents of alcohol left (and I doubt it) after a wee bit, it is not going to affect the epoxy at all.

One other note - to avoid the wood from degassing and introducing air bubbles into the epoxy, you should raise the heat/temp in the room for a bit BEFORE you apply the epoxy. Then let it start to cool off, and coat. The air in the wood cells will cool, and actually draw in epoxy rather than the opposite (if you raise the heat and then start to coat, the air in the wood cells expands and starts to exit the pores and you get bubbles. If that makes sense.

AJC

[cabnet636]

Probably should have remembered and posted that we had an employee seal all the edges of a bar with "silicone" so as the material would not leak out,,, had to remove, throw away and replace a 3500.00 bar top. it will not stick to waxes nor synthetics,

[dlcw]

Wanted to update everyone on progress. Used many excellent pieces of advice from this thread and put the seal coat on yesterday, sanded it today and put the first thick (1/16") coat on today. Used a Milwaukee heat gun on air bubbles and the top looks beautiful.

I'm glad I didn't have to use the torch as the flame is just to hot and concentrated for my comfort. The heat gun doesn't get hot enough to burn the epoxy but is plenty hot to pop air bubbles.

I will post pictures of the finished tables when I get them done.

Thanks again everyone.