Anyone here try a magnetic stirrer for mixing epoxy?

You know, the type they use in labs?  The reason I ask is because I was thinking it might help to reduce bubbles or purge them for the finish coats.  

That gets me to thinking of using vacuum to degass the resin after mixing it.  

I’ve never used a magnetic stirir with our resins, but I have spent a significant amount of time using them- and I’m pretty sure they wouldn’t cut it. The typical ~inch long stirir I don’t think will be able to adequatly handle the viscotiy of our resins and more importantly, would definetly not be capable of scraping all the sides and bottom. 

I find the key to getting less bubbles is just stirring a little slower and steadier, but vaccum degassing does work super well if you have a convienant setup. 

I stir pretty slowly but I stir for so long that it’s inevitable to get some bubbles, even when I let the mix set for a bit to settle down.  

I could see using a mason jar and running the vacuum connection through the lid, similar to how they make the reserve tanks out of PVC pipe for the vacuum rigs. Drop the cup into the far, screw the lid on, connect the vacuum and let it run for a couple minutes.  For that matter, a tupperware container could possibly work.  

I wonder how long it would take to degas a few ounces of epoxy?  

G, I’ve mixed soybean oil with a magnetic stirrer, making biodiesel. I think it would work with epoxy, too. You can crank up the rpms on the stirrer so that it would get the epoxy going. I’m not sure if it’s worth buying a stirrer set up, though. I think vacuuming the pot is a much easier solution.  

I cant imagine it working,  Epoxy is too thick and sticky.  You are never going to be able to scrape the sides of the container into the mix, and when the unmixed sides drip onto your work…

I haven’t tried it, but I have my doubts.  In a vacuum, the bubbles will stay in suspension, because a vacuum isn’t forcing them upwards, and out of the mix.  They might get larger, as pressure decreases, but epoxy is too viscous to allow them to effervesce like champaign.


quick, easy, cheap, greatly minimizes bubbles, helps with wetout…

take a

What Chrisp says. Howzit?


When you mix you use a big stir stick like a paint stick. Heat up the epoxy side…mix in the hardner side, then use a paint stick to fold the epoxy into itself. All you have got to do is NOT whip it into a frothy mess.  Mix the sides, mix it going right, mix it going left. mix it side ways. mix it cross ways…put it on the board.  Get the mix sticks free fro HD.

You don’t need to electric mag, vac bag, 6 finned, simmons, spoonshaped, freak show it.

Sorry Gdaddy…not shouting at you…just doing it in general about epoxy.

I get great bubble free finishes on resin table tops by flashing the surface with a heat gun. I tried it years ago on an epoxy board gloss coat and it also worked great.  The heat pulls bubbles to the surface and they disappear.

  Actually a propane torch works better but that is another story.

cleanlines, what kind/brand of resin are you using for those table tops?

I’ve always wanted to make one

I have been using this.

I agree that mixing and heat is far easier than vacuum degassing- but as an FYI- it works really well and it makes sense that it should work so well. Simply put, the vacuum lowers the vapor pressure and gets the bubbles out much faster. Try boiling water at high altitude- the required temperature to “vaporize” aka boil water is lower because of the same change in vapor pressure. That’s why sodas are carbonated under pressure and why they bubble when you open them up.


I use a large stick, I stir real slowly and fold it in; I don’t whip my resin into a froth and I do let it sit for a minute or two to let it exotherm a little, so I am warming it.  . I’m not getting a lot of bubbles but neither is it bubble free.  I was just casting about for a way to improve on what I’m doing.  


I used to build custome trolling rods for offshore sportfishing boats.  The trick to bubble free finishes was a little heat as the rod turned on the drying machine.

I just went on the aero marine site. the bartop epoxy is not UV stable, and will yellow

Gdaddy, you really should try microwaving your resin.

Not the hardner, just the resin.

Does wonders

Aero marine is for resin tables not surfboards. I was answering a question about resin tables.

My point was that the heatgun/torch method works on boards also. I did it years ago glossing a board with RR epoxy.