#1 Bubble Blog: AVOID BUBBLES When Mixing Resins!

• How to best mix and dispense epoxy resins, AND avoid bubbles in resin?
• Semi-automatic mixer.
• Hand mixing to avoid bubbles.
• Apply a seal coat to avoid bubbles arising from air in wood.
• How to totally AVOID bubbles in resin? 100%? Use Static Mixers!

• Stokes Law.  Bigger bubbles rise faster than smaller bubbles.
• How much faster do bubbles rise from lower viscosity resins? See for yourself!

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YOU ARE HERE!
#3 Bubble Blog: Get bubbles OUT of resin!

• Fast mixing with a drill and mixer whips bubbles deep into epoxy resins!

• Removing air bubbles from deep within resins: Vacuum degassing.

• What to AVOID (Solvents, and Heating), and what to DO!

• Removing air bubbles from the surface of resin pours.

• What to AVOID (Propane Torches!), and what to DO!
  

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SUMMARY:  If you’re the kind of person who wants to “cut to the chase,” then here’s the short version of all three blogs relating to bubbles:  Use the lowest viscosity resins you can find that work in your applications, coupled with the longest gel time.

• FACT: Most professional woodworkers do not vacuum-degas their epoxy resin mixes, especially if in production because it takes time. (It’s always a good idea though.)
  
  
• FACT: Most professional woodworkers mix their resins fast, with a mixer on a drill, which whips in loads of bubbles. Why? Because it saves time.
  
  
• FACT: Usually, professionals simply rely on bubbles in epoxy resin
  formulations to naturally rise to the top. Then they “pop” the bubbles in one of several ways (read on)
  .
• If the above limitations are YOUR practical reality as well, then the ONLY way to do BETTER, is to buy low viscosity epoxy resin that gels slower, as professionals do, because:
• Bubbles rise faster from lower viscosity resins (i.e. thinner, less thick resins).
• Slower gelation times allow a longer time for bubbles to rise out of resins.

Solution! Lowest Cost ($59.99/gal. delivered + tax), BEST Deep Pour Epoxy.

• The BEST epoxy resin for woodworking, for deep pour applications like casting river tables, is PRO EPOXY plus PRO HARDENER (185 cps, mixed, for the fewest micro bubbles), from Eco-nomicResins.com.
• It has the longest gel time (~24 hrs.), the lowest exotherm for deepest pours (4”), is the clearest, and has the best UV protection: UV Absorbers + HALS.
• It can also be used in epoxy COATING applications (0.05-0.25”), with 4% PRO ACCELERATOR, like seal-coating with a 6-hour gel time, tacky and ready to adhere to a deep pour the next day.

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#3 Bubble Blog: How to get bubbles OUT of resins?

First, we’re going to discuss how to eliminate bubbles from within the volume of deep pour epoxy, and later we’ll talk about how to eliminate bubbles on the surface. How do they get there in the first place? Usually, it’s from FAST MIXING.

Fast mixing with a variable-speed drill and mixer whips bubbles into deep epoxy mixes! 

Despite concerns about entrapping bubbles in resin, this is how most professional woodworkers mix epoxy resins, because it saves time! They simply use a variable speed drill and a mixer, with 5-gallon buckets for big projects. This approach absolutely whips air into epoxy resin mixes, as you can see for yourself!

Removing epoxy bubbles from deep within resin pours

How to get air bubbles out of resin? First, we'll discuss what NOT to do, and why.

NOT RECOMMENDED ways to degas bubbles mixed deep in resins:

• ADDING SOLVENTS to lower the viscosity. While this WILL help bubbles to rise faster, AND is commonly done, adding solvents should be avoided for all the following reasons:
  
  
• NOT RECOMMENDED: Adding solvents for low viscosity resin just adds polluting VOCs to the atmosphere and your workspace. Once solvents are added, you no longer have a low-VOC resin! These can also damage your health.
  
  
• 
  NOT RECOMMENDED: Solvents added to epoxy resin mixes can also create a fire hazard. For example, acetone (highly flammable) is often used to reduce the viscosity of epoxy resin mixes. Next, users often apply a propane flame to burst the surface resin bubbles. Bad idea! At BEST, highly dangerous!
  
  
• Wastes Money: Acetone and MEK are fairly expensive. Would you stand in the wind throwing $5 and-$10 bills away, like an idiot? This is exactly what you’re doing when you add solvents. Plus, it’s polluting. You deserve better! Why not just buy low viscosity resin in the first place?
  
  
• Heating the resins prior to mixing them: NOT RECOMMENDED: True, this will make for a low viscosity epoxy resin, which would help bubbles in epoxy rise faster.
  
  
• But, at the same time, you’re also dramatically speeding up gelation, which will give resin bubbles less time to rise.
  
  
• A related problem is that the reaction rate doubles with every 10°C increase. Most woodworking epoxy resins are formulated to cure at room temperature. If you cure epoxy resin kits at hotter temperatures, you’re MUCH more likely to get run-away thermal reactions causing epoxy resins to yellow, crack, char, or burn! This an issue especially with deep pour epoxy resins, because of the larger masses of epoxy resin involved.

RECOMMENDED ways to get bubbles OUT of resin, especially deep pours!

OK, so you mixed fast like the rest of us often do. No surprise, your resin is FULL of bubbles, too! At this point there are only TWO recommended ways to minimize bubbles deep within a resin pour:

• Let the bubbles rise, slowly and naturally, out of the resin. As noted earlier, this is the most common approach that professional woodworkers use when making a deep pour epoxy river table.
  
  
• Use high-quality deep pour epoxy, with low-viscosity resin and long gel times!
  
  
• If your deep pour resin did not degas well enough on its own, then next time, USE A LOWER VISCOSITY, LONGER GEL-TIME RESIN! The lowest viscosity deep pouring resin is PRO EPOXY and HARDENER with 185 cps mix viscosity. It also has the longest gel time: typically ~24 hours at 72°F!  You will experience 127% fewer bubbles at any given time, and for any given bubble size vs. Super Clear 2.0 epoxy mix.  Super Clear 2.0 has a viscosity of 420 cps, more than double that of PRO EPOXY and PRO HARDENER. PRO EPOXY and HARDENER is the best epoxy for no bubbles!  www.RiverTableEpoxyResins.com.
  
  
• 
  See for yourself.  Check for yourself.  Decide for yourself.  You can compare 40+ Deep Pour epoxy resin kits, and 50+ Coating epoxy kits, via the “2023 Epoxy Resin Online Buyers Guide for Woodworkers,” with all data and delivered price/gallon (including sales taxes), straight from the suppliers’ webpages. We even show the formulators’ live links so can check everything out for yourself.

Use degassing chamber with resin before pouring!  It’s the “gold standard” for eliminating bubbles.

• If you haven’t poured it yet, there’s still time for this! A vacuum degassing chamber works because when you pull a vacuum, the bubbles grow enormously. Large bubbles rise much faster than small bubbles (Stokes Law, #2 Bubble-Blog). A degassing chamber also thins the bubble walls at the surface. This allows them to pop faster. Hence, what would have taken hours (if ever) to occur naturally, takes place in minutes instead.
  
  
• 
  
  Vacuum degassing chamber and pump kits are priced from $105 (for a 1.5-gallon resin degassing chamber and pump) to $349 (Amazon) for the “9-gallon PBAutos” kit shown below. It also has a thick tempered glass lid. (The acrylic plastic lids on most degassing chambers will crack when exposed to solvent vapors.) Further, the degassing chamber is stainless steel, while most others are just chromium-coated steel. What’s UNIQUE about the 9-gallon PBAutos degassing chamber is that it can readily accommodate at least certain designs of 5 gallon plastic buckets.
  
  
• Note that not all 5 gallon buckets will fit inside this particular chamber. In fact, most 5 gallon buckets will NOT fit. Only some will do. In order to fit inside, the outside diameter including reinforcing rings around the top of the 5 gallon bucket must be less than 13.5” W at the widest spot, and the full height of the bucket must be less than 13 7/8”). One manufacturer of 5 gallon buckets that do fit is Encore Plastics Corp., Cambridge, OH, 1-800-336-2673, 65 mil. Polyethylene, model 13938.
  
  
• United States Plastic Corp. sells the above 5 gallon buckets in small quantities, which easily fit the above degassing chamber. USP’s description of this exact 5 gallon bucket follows: Top OD=1.9”, Bottom OD=9.77”, Height=13.62”, wall=0.7”, Stock#=2306 bucket, ($7.54 each) and Stock #2332 Lid, ($3.13 each, but with the lid ON the bucket will no longer fit the interior height of the degassing container.  www.USPlastic.com. 
  
  
• Degassing resin before pouring: It’s always a great idea! The top on every degassing chamber is clear, so you see at a glance when no more bubbles are foaming up and popping. The only downside is the cost of the degassing chamber and pump, and the time involved. How long to degas resin? It can easily take 15 minutes for degassing resin.

Removing SURFACE bubbles in epoxy and what to AVOID when removing surface bubbles in resin (Propane Torches!, and more):

• Do secret “degassing resin additives” work? Rarely! They are NOT the BEST answer for "How to get bubbles out of resin!"
  
  
• The main thing these surface-active additives do is alter the surface tension, so resin bubbles that have already risen to the surface pop faster. The additives used to help surface bubbles in epoxy pop are chemicals like modified silicone oils that usually have harmful effects beyond changing the surface tension.
  
  
• Even technical chemists (who have been sales representatives for the best known antifoaming agents for resins, for DECADES) agree that lowering resin mix viscosity is OVERWHELMINGLY more effective at getting rid of bubbles in resin than defoamers.
  
  
• 
  However, adding modified silicone oils and the like to a formulation may seriously damage the future adhesion of topcoats and varnishes, or cause fisheyes in them. Avoid resin formulations that indicate they have “proprietary additives” (shh!) to make resin “degas faster!” That’s usually B.S.: You should have NO FOMO (sorry) if your resin doesn’t have these additives; quite the opposite. There are better answers for, “How to remove air bubbles,” from the SURFACE of resins, discussed below.
  
  
• PRO EPOXY and PRO HARDENER resins contain NO damaging surface-active agents like modified silicone oils. PRO EPOXY and PRO HARDENER are also far-and-away the most eco-friendly resins, with 34% bio content, as well as the most economical epoxy deep pour resins, $59.99 delivered, including sales tax in the price. www.RiverTableEpoxyResins.com. See for yourself, check for yourself decide for yourself, with the “2023 Epoxy Resin Online Buyers Guide for Woodworkers.”
  
  
• ALSO NOT RECOMMENDED: Most woodworkers working with epoxy resins use a propane torch. It pops surface resin bubbles immediately as shown further below, BUT has two drawbacks:
   
• Fire hazard: Avoid open flames in your shop whenever possible. 
• Creates yellowing carbamates: The flame generates carbon dioxide (CO2) right at the surface of the resin. CO2 reacts almost instantly with the amines in the B-Side hardener, to form carbamates. These can cause “amine blush” or a white film on the surface of the resin. Some of the carbamates will get mixed down into the resin.

• 
   Carbamates are one of the leading causes of epoxy yellowing. You instantly handicap the long-term appearance of your epoxy castings when using a propane torch.
   
• A NO-NO! We especially do not recommend pouring a half inch of mixed epoxy, torching, and then repeating this process three or four times! This puts way more yellowing carbamates into your resin than you want!
  
  
• Propane torches can also damage costly, reusable silicone or HDPE molds! Replacing the propane tanks costs money too.
  
  
• It’s easy but there are better alternatives, which are just as fast, safer and do not create yellowing in your epoxy resin casting.
  
  

Use a heat gun, with a force-concentrating nozzle:  Hot forced air pops resin bubbles!

• Some woodworkers believe that it’s the CO2 (carbon dioxide) from the propane torch that pops resin bubbles on the surface, but it’s mainly the heat. The heat causes bubbles to swell and pop. It also instantly reduces the viscosity of the resin in thin bubble walls, which weakens the bubbles. The force of the hot air also contributes to bursting resin bubbles on the surface of epoxy resins.
  
  

• Heat gun choices for bubble elimination:

• 
  NOT RECOMMENDED: “El Cheapo.” There are $12 plastic hot air guns available from Amazon and others that ACTUALLY WARN YOU IN THEIR OWN ONLINE DESCRIPTIONS that they’ll melt when used longer than 3 minutes! These also lack a heat-funneling tip to better mimic a propane torch.  WOWZA! AVOID!
  
  
• ALSO NOT RECOMMENDED: A Hair Dryer. Do not use a hair dryer either. The heat and force of a hair dryer or hair blower are NOT intense enough. A real heat gun (which IS recommended) can help you bend a copper pipe, and would burn your hair right off.
  
  
• 
  Best,” and “OK” Heat Gun Choices. 
  

  Both have HEAT-CONCENTRATING NOZZLE TIPS, KEY to mimicking the tip of propane torches!

• An advantage of having a good heat gun, with a HEAT CONCENTRATING NOZZLE TIP is that in addition to “bursting your bubbles,” it can also be used for making ‘epoxy resin art,’ and creating special effects like “waves on the beach.” 
  
  
• For “waves on the beach,” the heat gun blows back a poured line of white epoxy, feathering it out to create a birds-eye look of crashing waves. It looks surprisingly easy with a heat gun, and it’s beautiful. You can’t do THAT with a propane torch!  Why buy both?
  
  

• Pop surface bubbles in resin with a fine spray of 91% IPA:
  
  
• The third way to get rid of bubbles from the surface of your epoxy pour is to spray them lightly with a FINE MIST of 91% IPA (isopropyl alcohol). This will change the surface tension, and instantly pop the surface bubbles in resin. The tiny amount of IPA present will quickly evaporate.  70% IPA has too much water.  99% IPA costs too much.  91% IPA is the best solvent and spray-mist for epoxy resin.
  
  
• Don’t use a hand sprayer that puts out coarse drops. These will take too long to evaporate and may leave “fisheyes” on your resin surface. A light mist of IPA spray will instantly pop surface bubbles in resin!
  

Do nothing! You may not need to worry about SURFACE resin bubbles at all!

• If you’re going to plane your final cured pour or sand it, then any surface resin bubbles will be automatically removed. In this case, surface bubbles in resin need not be popped before full cure.  That would just be a waste of time.
  
  

The end, #3 Bubble Blog: How to Get Rid of Bubbles IN resin.

#1 Bubble Blog: Avoid Bubbles When Mixing Resins.

• Discusses how to mix and dispense epoxy resins while minimizing or 100% avoiding all micro bubbles in the first place.

#2 Bubble Blog: Use Low Viscosity, Long Gel-time Resins.

• Discusses the importance of low viscosity resin and long gel times for how to get bubbles out of epoxy.

#3 Bubble Blog: How to Get Rid of Bubbles IN Resin.

• This blog on “How to get bubbles out of resin,” discusses the resin degassing chamber, as well as how to get rid of bubbles in resin SURFACES.