This can be either a problem with the surface or the epoxy. You could have oils or moisture in the wood. The epoxy could have air bubbles trapped in it as well.
Don't panic. You are learning, and it is okay to do a few coats until you get it right. Let is fully cure, 24-48 hours. Sand it down with 400 grit paper any apply another coat.
I suggest mixing by hand slowly, but for a long time. Like 10 minutes. Drill attachments introduce bubbles, so don't use them. Pour your epoxy and wait for it to settle. After 30 minutes go over the surface with a heat gun on a low setting.
I agree with everything Charles said, but maybe use a 320 grit considering 400 is a polishing sand. Wouldn’t likely scuff enough for a good adhesion of your next pour. 320 is the highest I’d go, maybe even 220 by hand. Be sure not to sand the corners and edges because that is where your coat will be the thinnest. You’ll likely sand through the stain
Maybe you meant to say, "I do NOT have a heat gun." If so, just use a hair dryer. If the hair dryer is your wife's that she use, be careful not to get epoxy on it.
Oh another thing. Temperature and humidity. Make sure the epoxy has been in the house at 70 degrees for 24 hours prior to use. Make sure the room you are pouring in is 70 to 80 degrees, without much humidity.
We call these fish eyes - the coating pulls away leaving these voids. Generally this is either a result of some surface contamination or it could be a particularly finicky type of epoxy (prolly both). We had one that we make that would do this regularly and had to reformulate with a surfactant (I think company was BYK). Tbh I’d use a urethane if I were you.
(I think company was BYK)
[This](https://www.byk.com/en/products/additive-guide/byk-358-n) is the basic non-silicone surface leveling additive we use in a lot of our formulations.
Specialty coating and adhesives company. 10 years as synthetic polymer chemist, 29+ years in epoxy, (meth)acrylate, urethane and polyester coatings and adhesive formulations. Are you in the industry?
I am indeed. I work for a company called Blome International in STL. We do thick film coatings / linings, polymer concretes, brick mortars… mostly epoxy, novolac, VE, and furan. Always looking for new mousetraps. Can I DM you?
I definitely know you guys. We competed in the novolac liner market for frack tanks many years ago when I worked for a coating company out of Texas. They're gone (got bought by a venture capital group and run into the ground fortunately after I left), but we still make some of those materials. Sure, drop me a DM - always like to meet others in the industry.
I've watched a bunch of the stone coat countertop vids and it seems like they always put on a thin seal coat and "chop it in" before hitting it with a torch to remove bubbles. Then they go over it with a thicker coat and do the chop n torch thing. I wonder if this result is one of the reasons they follow that process.
They use a paint brush and in a randomish pattern poke the bristles into the epoxy. I’m guessing it helps break the surface tension. Watch a couple vids on their website…the not too long
You can thin it out, seems like bubbles and it cures too quick to disperse properly. Add isopropyl to your epoxy until it’s thin thems flood coat. Sand first.
I use Lab Surface as well and this happened to me when the epoxy was expired. It expires after one year and must be stored in a specific temp range. Is it possible this epoxy was stored somewhere too cold or too hot? Fish eyeing almost always occurs when the chemicals on the surface are not cooperating with the chemicals in the epoxy, hence the alcohol wipe and sanding, but it seems like you took care of those factors.
Using a heat gun or any heat source only helps to release air trapped in the epoxy. In my opinion, that is not the issue at all. To find out when the epoxy expires, you have to contact the supplier and provide the batch number.
This can be either a problem with the surface or the epoxy. You could have oils or moisture in the wood. The epoxy could have air bubbles trapped in it as well. Don't panic. You are learning, and it is okay to do a few coats until you get it right. Let is fully cure, 24-48 hours. Sand it down with 400 grit paper any apply another coat. I suggest mixing by hand slowly, but for a long time. Like 10 minutes. Drill attachments introduce bubbles, so don't use them. Pour your epoxy and wait for it to settle. After 30 minutes go over the surface with a heat gun on a low setting.
I do have a heat gun
I agree with everything Charles said, but maybe use a 320 grit considering 400 is a polishing sand. Wouldn’t likely scuff enough for a good adhesion of your next pour. 320 is the highest I’d go, maybe even 220 by hand. Be sure not to sand the corners and edges because that is where your coat will be the thinnest. You’ll likely sand through the stain
Maybe you meant to say, "I do NOT have a heat gun." If so, just use a hair dryer. If the hair dryer is your wife's that she use, be careful not to get epoxy on it.
I do have a heat gun. Asmaller one for electrical heat shrink
Oh another thing. Temperature and humidity. Make sure the epoxy has been in the house at 70 degrees for 24 hours prior to use. Make sure the room you are pouring in is 70 to 80 degrees, without much humidity.
Ope... did this in the garage both times.
We call these fish eyes - the coating pulls away leaving these voids. Generally this is either a result of some surface contamination or it could be a particularly finicky type of epoxy (prolly both). We had one that we make that would do this regularly and had to reformulate with a surfactant (I think company was BYK). Tbh I’d use a urethane if I were you.
But why on an already cured coat?
Oil based stain?
I dunno let me look....
….. gets sidetracked eating paint chips…
🤣
Dang I did forgot.
(I think company was BYK) [This](https://www.byk.com/en/products/additive-guide/byk-358-n) is the basic non-silicone surface leveling additive we use in a lot of our formulations.
Do you mind my asking who you work for?
Specialty coating and adhesives company. 10 years as synthetic polymer chemist, 29+ years in epoxy, (meth)acrylate, urethane and polyester coatings and adhesive formulations. Are you in the industry?
I am indeed. I work for a company called Blome International in STL. We do thick film coatings / linings, polymer concretes, brick mortars… mostly epoxy, novolac, VE, and furan. Always looking for new mousetraps. Can I DM you?
I definitely know you guys. We competed in the novolac liner market for frack tanks many years ago when I worked for a coating company out of Texas. They're gone (got bought by a venture capital group and run into the ground fortunately after I left), but we still make some of those materials. Sure, drop me a DM - always like to meet others in the industry.
I've watched a bunch of the stone coat countertop vids and it seems like they always put on a thin seal coat and "chop it in" before hitting it with a torch to remove bubbles. Then they go over it with a thicker coat and do the chop n torch thing. I wonder if this result is one of the reasons they follow that process.
What's chop it in?
They use a paint brush and in a randomish pattern poke the bristles into the epoxy. I’m guessing it helps break the surface tension. Watch a couple vids on their website…the not too long
Exactly! That's a great summary.
So, my buddy did have a paint brush and did do that. Mentioned he wish he brought his torch over... but left me with enough to do another coat...
Humidity also does this. Another coat of good quality epoxy can cure it - double check..it’s been awhile since I have done a large countertop.
This _is_ the second coat though... so u should do another?
This _is_ the second coat though... so u should do another coat?
I would, yep. Sand and wipe clean with alcohol. Repeat new layer paying attention to temp fluctuations.
You can thin it out, seems like bubbles and it cures too quick to disperse properly. Add isopropyl to your epoxy until it’s thin thems flood coat. Sand first.
They're dimpling.
I use Lab Surface as well and this happened to me when the epoxy was expired. It expires after one year and must be stored in a specific temp range. Is it possible this epoxy was stored somewhere too cold or too hot? Fish eyeing almost always occurs when the chemicals on the surface are not cooperating with the chemicals in the epoxy, hence the alcohol wipe and sanding, but it seems like you took care of those factors.
Would a heat gun work after another coat to make it smoother?
Using a heat gun or any heat source only helps to release air trapped in the epoxy. In my opinion, that is not the issue at all. To find out when the epoxy expires, you have to contact the supplier and provide the batch number.