Results 1 to 33 of 33

Thread: Penetrating Epoxy kicked off

  1. #1
    Join Date
    Jun 2018
    Location
    Lake Odessa, Mi, USA
    Posts
    73

    Default Penetrating Epoxy kicked off

    Had my first go with penetrating epoxy last night and it did not go as planned. I was using Jamestown Dist 2 part system. Measured very carefully and tried to move quickly. First I noticed my cup was getting warm, then came the smoke and then bam I had Jello. Checked my watch and it had been 12 minutes since I had stirred. The boat is wrapped so it was very warm. I think I got the 2-1 ratio correct. Should I use less hardener next time? Is it that temp sensitive? I'm guessing I did not get much penetration.

  2. #2
    Join Date
    Jan 2009
    Location
    se pa (Bristol PA)
    Posts
    3,106

    Default

    Epoxy needs to be exact measured not like polyester resin.

    mixing in a cup will almost guarantee it will kick way faster than necessary, as soon as you mix it transfer it to a shallow container.

    If you're working time and kick times can't overlap, look for a slower hardener not using less or more hardener.
    Denise, Bristol PA, Oday30, Anchor Yacht Club, On tidal Delaware River. my current project; http://forum.woodenboat.com/showthre...0-Ducker-Resto

  3. #3
    Join Date
    Dec 2003
    Location
    Portland, Oregon
    Posts
    51,287

    Default Re: Penetrating Epoxy kicked off

    This is confusing. Can you share a link to the specific product you used?
    David G
    Harbor Woodworks
    https://www.facebook.com/HarborWoodworks/

    "It was a Sunday morning and Goddard gave thanks that there were still places where one could worship in temples not made by human hands." -- L. F. Herreshoff (The Compleat Cruiser)

  4. #4
    Join Date
    Apr 1999
    Location
    Hyannis, MA, USA
    Posts
    45,882

    Default Re: Penetrating Epoxy kicked off

    Epoxies can go wildly, frighteningly, exothermic if mixed in a hot environment, if the pot is left in sunlight, and if the volume is the pot makes it essentially self-cooking. The easiest cure is to mix much smaller batches and spread it fast. A volume sitting around in a pot for twelve minutes is eight to ten minutes too long.

    Do not deviate from the mix ratio. That's not your problem.

  5. #5
    Join Date
    Sep 2010
    Location
    Bainbridge Island WA
    Posts
    2,616

    Default Re: Penetrating Epoxy kicked off

    Don't mess with the mix ratio.

    Yes, epoxy is heat sensitive and will set faster when warm, it also generates heat as it sets up so trying to keep it in a "cup" will lead to setting faster. Penetrating epoxy, eh? I'm guessing you are spreading it over a large surface. Pouring the mixed epoxy into a shallow pan helps. Or you could try pouring it out of your mixing cup onto the boat and smearing it around from there.

    I use System3 and have found it helpful to have their fast and slow hardeners on hand, once my shop goes from the usual mid-60s into the 70s I switch to the slow stuff. I don't know if there is a slow setting penetrating epoxy for use in warmer temperatures.
    Steve

    Boats, like whiskey, are all good.
    R.D Culler

  6. #6
    Join Date
    Jun 2003
    Location
    Central Coast, Ca
    Posts
    21,663

    Default Re: Penetrating Epoxy kicked off

    The first dumpster fire I ever saw was caused by an apprentice mixing up a pint of epoxy in a quart jar. It quickly became to hot fot him to hold and started smoking. He was frightened and tossed it in the dumpster. Then it went off!!
    The trick for large amounts is to make it up in smaller batches and immediately spread it out onto a sheet of plastic film. Spread out thin like that you could get maybe an hour of work time. (West System has three different speeds of hardener)

  7. #7
    Join Date
    Jun 2018
    Location
    Lake Odessa, Mi, USA
    Posts
    73

    Default Re: Penetrating Epoxy kicked off

    Does the pump set-up help with mixing up really small batches? Last night I only mixed up to the smallest markings on the mixing cup(maybe an ounce) they had sent me and ended up throwing half of that away. Sounds like I need a process for really small batches. Hopefully it also cools off a bit.

  8. #8
    Join Date
    Jan 2013
    Location
    Nashville
    Posts
    121

    Default Re: Penetrating Epoxy kicked off

    Purchase an inexpensive kitchen scale to measure by weight for small batches. Really only needed when mixing less than 3oz of equivalent volume though for 2:1 ratios. 3oz volume or more in marked cups is easy with pumps.

    Pouring the mixed epoxy into a wide flat tupperware container spreads it out and helps reduce the heat build up. Also any leftover cured epoxy in the plastic container will just pop out to reuse the container.
    Last edited by bnaboatbuilder; 09-18-2018 at 10:03 AM.
    - John

  9. #9
    Join Date
    Dec 2016
    Location
    Long Island Sound - no wind land
    Posts
    54

    Default Re: Penetrating Epoxy kicked off

    ice bath

  10. #10
    Join Date
    Apr 1999
    Location
    Hyannis, MA, USA
    Posts
    45,882

    Default Re: Penetrating Epoxy kicked off

    For epoxies that don't have pumps and for batches too small for even the smallest pump, I mark small cups or even clear tubes used like a pipette. One for resin, one for catalyst, third wider for mixing. Fast, easy, accurate. Especially with a penetrating sealer like CPES, you don't need to worry about such things as getting it all down in one go.

  11. #11
    Join Date
    Mar 2015
    Location
    Victoria BC Canada
    Posts
    263

    Default Re: Penetrating Epoxy kicked off

    Quote Originally Posted by jstafford View Post
    Does the pump set-up help with mixing up really small batches? Last night I only mixed up to the smallest markings on the mixing cup(maybe an ounce) they had sent me and ended up throwing half of that away. Sounds like I need a process for really small batches. Hopefully it also cools off a bit.
    Check your measuring cups for accuracy.
    Use water and an accurate measure from a kitchen measuring cup to check.
    I have found some inaccuracies in my disposable measuring cups, adjusted and have had no problems measuring epoxy by volume.
    Other than thorough mixing, measuring is the most important variable when working with epoxy.
    I wouldn't wait for the weather to cool down, just get some "slower" ( higher temp ) hardener.

  12. #12
    Join Date
    Dec 2003
    Location
    Portland, Oregon
    Posts
    51,287

    Default Re: Penetrating Epoxy kicked off

    As always... reading the instructions helps. West System kindly makes all sorts of instructional info available as a free download. Use it. I esp. recommend "... on Boat Construction" for a comprehensive reference. At our shop, we call it 'the epoxy bible'.

    https://www.westsystem.com/instruction-2/
    David G
    Harbor Woodworks
    https://www.facebook.com/HarborWoodworks/

    "It was a Sunday morning and Goddard gave thanks that there were still places where one could worship in temples not made by human hands." -- L. F. Herreshoff (The Compleat Cruiser)

  13. #13
    Join Date
    Jun 2018
    Location
    Lake Odessa, Mi, USA
    Posts
    73

    Default Re: Penetrating Epoxy kicked off

    Forgot I took a couple pics. This is after it kicked off. I started off at the 1 mark.20180917_185710.jpg20180917_185648.jpg

  14. #14
    Join Date
    Nov 2011
    Posts
    5,621

    Default Re: Penetrating Epoxy kicked off

    Penetrating epoxy is thin enough that you can chill it and still be able to measure accurately and mix easily. Once it's mixed pour it into a chilled metal paint roller pan then spread it quickly. It's not varnish, just get it out of the pan and onto the wood.

  15. #15
    Join Date
    Oct 2017
    Location
    Charleston, SC USA
    Posts
    83

    Default Re: Penetrating Epoxy kicked off

    I use a $15 digital scale minus the tare weight of a disposable cup to mix epoxy by the gram. Accurate with any volume.
    Why does anybody use the crude measurements of pumps and dispenser cups for mixing epoxy?

  16. #16
    Join Date
    Mar 2015
    Location
    Victoria BC Canada
    Posts
    263

    Default Re: Penetrating Epoxy kicked off

    Quote Originally Posted by Arlc View Post
    I use a $15 digital scale minus the tare weight of a disposable cup to mix epoxy by the gram. Accurate with any volume.
    Why does anybody use the crude measurements of pumps and dispenser cups for mixing epoxy?
    Because I need a container to mix in anyway, why not measure it out in the same container, checked and calibrated for accuracy and with no problems.
    That's why.
    No need for a $15 dollar scale, that could fail.
    But to each their own, carry on.

  17. #17
    Join Date
    Dec 2003
    Location
    Portland, Oregon
    Posts
    51,287

    Default Re: Penetrating Epoxy kicked off

    Quote Originally Posted by Tom Christie View Post
    Because I need a container to mix in anyway, why not measure it out in the same container, checked and calibrated for accuracy and with no problems.
    That's why.
    No need for a $15 dollar scale, that could fail.
    But to each their own, carry on.
    I'm happy enough to trust the pumps in most cases. Never had a failure except when volunteers - building boats for a local kids rowing club - lost track of the # of squirts.

    For very small quantities, and for epoxies that come in other sorts of containers - the kitchen scale approach works a treat. I've used the present one for maybe 10 years without a failure. The problem with containers - for small quantities - is the 'meniscus effect'. That effect is small enough to be irrelevant in larger containers... but becomes relevant for small dabs. The weight measure of a scale is an approximation of the correct ratio also... but a consistent approximation. There are conversion tables available if you want to be fussy... but I've never had an issue with simply using the weight ratios instead of volume ratios.

    Again I'll urge anyone who does more than one project in their life (and maybe even them... maybe esp. them?) to read the book I referenced above.
    David G
    Harbor Woodworks
    https://www.facebook.com/HarborWoodworks/

    "It was a Sunday morning and Goddard gave thanks that there were still places where one could worship in temples not made by human hands." -- L. F. Herreshoff (The Compleat Cruiser)

  18. #18
    Join Date
    Jul 2011
    Location
    Lindstrom, MN
    Posts
    2,279

    Default Re: Penetrating Epoxy kicked off

    Quote Originally Posted by jstafford View Post
    Had my first go with penetrating epoxy last night and it did not go as planned. I was using Jamestown Dist 2 part system. Measured very carefully and tried to move quickly. First I noticed my cup was getting warm, then came the smoke and then bam I had Jello. Checked my watch and it had been 12 minutes since I had stirred. The boat is wrapped so it was very warm. I think I got the 2-1 ratio correct. Should I use less hardener next time? Is it that temp sensitive? I'm guessing I did not get much penetration.
    Epoxy resin and hardener need to be mixed close to the exact ratio called for because they link together in a specific ratio. Too much of either part makes for a lot of unused links that want to react with something, and whatever they find won't be good.

    Polyester cures by a chain reaction where one resin molecule links to another, the second one grabs a third and so on to form a long chain until something goes wrong (like grabbing an oxygen atom, which is what the wax tries to prevent) or you run out of resin molecules.

    Were you using this stuff? https://doc.jamestowndistributors.co...DS_9.28.16.pdf

    The reason they give the gel time with the mass and starting temperature is that larger amounts go faster, smaller amounts go slower, warmer faster, cooler slower. "Gel Time at 75F, 150g mass, min. 45- 50" That's about 5oz, and it looks like a pretty slow hardener, so something isn't adding up here. Without knowing the temperature, volume, exact products used and age of the resin, it is hard to say why it kicked like that. The only (unlikely) thing about the age of the resin and hardener that I can think of would be where it was old and poorly sealed and the solvent had evaporated.
    Management is the art of counting beans. Leadership is the art of making every being count. --Joe Finch

  19. #19
    Join Date
    Jul 2008
    Location
    Modesto, CA
    Posts
    271

    Default Re: Penetrating Epoxy kicked off

    Quote Originally Posted by David G View Post
    I'm happy enough to trust the pumps in most cases. Never had a failure except when volunteers - building boats for a local kids rowing club - lost track of the # of squirts.
    I had trouble keeping track of the number of squirts, too, until I started doing alternate squirts - one squirt from part A, then one squirt from part B. I repeat until I have the volume needed. If I don't remember if that was 7 squirts or 8 squirts it doesn't really matter as long as I had kept alternating, and made the squirt from part B the last one.

  20. #20
    Join Date
    Jun 2018
    Location
    Lake Odessa, Mi, USA
    Posts
    73

    Default Re: Penetrating Epoxy kicked off

    Yes, that is the product I was using. Brand new bottles. Only mixed up about an once, I guess, double what the pic shows. I'm guessing from the other comments it was just too frigging hot. I don't have a thermometer on the boat but she is wrapped and it was around 86F and humid. So it was pretty toasty in that greenhouse. The materials had been on the boat waiting for me to use so they were warm to begin with.

  21. #21
    Join Date
    Mar 2001
    Location
    FL
    Posts
    237

    Default Re: Penetrating Epoxy kicked off

    Quote Originally Posted by Arlc View Post
    I use a $15 digital scale minus the tare weight of a disposable cup to mix epoxy by the gram. Accurate with any volume.
    Why does anybody use the crude measurements of pumps and dispenser cups for mixing epoxy?
    I have zero trouble measuring in containers and use everything from 2 oz plastic mouthwash cups, water bottles to quart or gallon water jugs. I cut all types of containers and mark them for accuracy. Epoxy is sensitive to mix ratios but not to the point of a scale being needed.

    Thrread drift...I see you are in SC. How are you doing with the flooding? I hope all is well. Peace.

  22. #22
    Join Date
    May 2016
    Location
    Ottawa, Canada
    Posts
    202

    Default Re: Penetrating Epoxy kicked off

    Hi,

    Note to check ratios if you are mixing by mass or volume. I know for a fact system three it's different. I always have my mix pot on a kitchen scale to check the pumps or to mix "half pumps".

    Cheers,
    Mark

  23. #23
    Join Date
    Feb 2000
    Location
    San Francisco Bay
    Posts
    11,694

    Default Re: Penetrating Epoxy kicked off

    I have mixed gallons and gallons of Smith and Co. CPES "Clear Penetrating Epoxy Sealer" and I have never, ever, had it go exothermic or even get warm. Never. Ever.

    Just sayin'.

    Regular WEST epoxy resins I've gone to the "slow tropical" hardener. I find it's easier to wait a bit longer for it to cure, enjoy the longer working time, and avoid the risk of an exothermic "cook off."

  24. #24
    Join Date
    Jan 2011
    Location
    Norwalk CT
    Posts
    1,007

    Default Re: Penetrating Epoxy kicked off

    Smiths CPES is much different than the Totalboat from Jamestown. I much prefer Smiths and have never had an issue with it kicking off. The Totalboat formula is much thicker and closer in viscosity to regular epoxy. I just started using it this summer and have not had it gel in the pot but I have been thinning it considerably with denatured alchohol.

    My guess is that it kicked because its in a pot and not in a tray.

  25. #25
    Join Date
    Apr 1999
    Location
    Hyannis, MA, USA
    Posts
    45,882

    Default Re: Penetrating Epoxy kicked off

    Good to know about CPES. I just projected from other epoxies and mix only as much as I can use in a few minutes.

  26. #26
    Join Date
    Jun 2018
    Location
    Lake Odessa, Mi, USA
    Posts
    73

    Default Re: Penetrating Epoxy kicked off

    Thanks everybody for all the tips and advice. I think my next go round will be much better.

  27. #27
    Join Date
    Jul 2011
    Location
    Lindstrom, MN
    Posts
    2,279

    Default Re: Penetrating Epoxy kicked off

    Due diligence. Juts to be certain, are you sure that you have the regular stuff, not the cold weather version? The cold weather version has a pot life of 10-15 minutes. At 85 degrees, the pot life of the regular stuff should have been longer than 15 minutes, but at 95F, 15 minutes wouldn't surprise me. Reaction rates tend to double when the temperature rises 10C, (from 75 to 93F) but that is a very rough rule of thumb.

    One big difference between this and CPES is the way they handle temperature. I think* CPES has an epoxy that is solif at room temperature, so it can dry 'hard' long before it cures. Lots of epoxy paints do this. The way CPES appears to handle temperature is to use fast or slow evaporation rate solvents with the same resin and hardener. Totalboat uses different hardeners that have different cure rates. If my assumption is correct, CPES would be a lot less likely to heat up and kick off at any reasonable temperature.

    *CPES hides their proprietary information in their SDS, so this conjecture is based on the one data sheet I found that slipped and said which resin they use. This is not to criticize them for hanging on to their trade secrets.

    FWIW Off topic for anyone crazy enough to try to glean information from a safety data sheet, I found a safety data sheet demystifyer, but haven't played with it. The site also has a glossary, so if you want to know what something like evaporation rate means, they explain it.

    EDIT:
    https://www.rotdoctor.com/products/cpes.html
    The different temperature formulations are only applicable during application
    and for a few days while it is curing.
    CLEAR PENETRATING EPOXY SEALER™ • CURE TIME CHART
    Pot Life At Temperature Warm Weather Formula Cold Weather Formula
    86F/30C 4 hours Not Recommended
    68F/20C 8 hours 2 hours
    50F/10C 16 hours 4 hours
    32F/0C Not Recommended 8 hours
    Full Cure Time Required
    86F/30C 2 days Not Recommended
    68F/20C 4 days 2 days
    50F/10C 8 days 2 days
    32F/0C Not Recommended 4 days
    WARNING: This product is inherently unsafe. It cannot be made safe. That's why it works so well. We recommend the use of a respirator capable of filtering organic solvent fumes and vinyl gloves during application.
    Last edited by MN Dave; 09-19-2018 at 10:40 PM.
    Management is the art of counting beans. Leadership is the art of making every being count. --Joe Finch

  28. #28
    Join Date
    Aug 2010
    Location
    Centerville Ma.
    Posts
    1,697

    Default Re: Penetrating Epoxy kicked off

    I find it difficult to get accurate measures with the small cups on anything less the the 2 line so I have measuring spoons for small batches. When coating a large area in hot weather it is good to have two people,one mixing small batches and one applying . It really speeds up the process without waste.

  29. #29
    Join Date
    Oct 2017
    Location
    Charleston, SC USA
    Posts
    83

    Default Re: Penetrating Epoxy kicked off

    I’ve used Raka epoxy for priming and sealing with Raka slow hardener. It flows more smoothly and has a better working time in warm temperatures than West/ Total Boat in my experience. I believe it’s formulation is better suited to southern climates. It’s much cheaper than West as well. Last time I bought it the price was $98 plus $15 shipping for a gallon of resin and 2 quarts slow hardener. I’ve had good results when it is 85-90 degrees in the shop.

  30. #30
    Join Date
    Oct 2010
    Location
    Central Vermont
    Posts
    319

    Default Re: Penetrating Epoxy kicked off

    When doing small glue jobs, I like to use West GFlex. It is a 1:1 ratio and I use metal kitchen measuring spoons or cups to easily get the ratio right. And it seems I always have plenty of time (i.e. 15 min plus) to spread out the glue.

  31. #31
    Join Date
    Mar 2009
    Posts
    1,212

    Default Re: Penetrating Epoxy kicked off

    I like small plastic medicine cups for mixing small amounts of epoxy. They hold one fluid ounce and have graduations accurate enough for the purpose. Just drip in 2.5 ml of hardener and 5 ml of resin, mix, add thickeners, all in the same pot. No waste left on measuring spoons, which can really upset your 2:1 ratio. That is about a 1/4 ounce batch, can't get much smaller.

    https://www.amazon.ca/Medicine-Cups-...46791156&psc=1

    Shows an example, I bought them at the local drugstore for not much more.

  32. #32
    Join Date
    Feb 2000
    Location
    San Francisco Bay
    Posts
    11,694

    Default Re: Penetrating Epoxy kicked off

    Quote Originally Posted by Ian McColgin View Post
    Good to know about CPES. I just projected from other epoxies and mix only as much as I can use in a few minutes.
    I've mixed CPES by the quart in coffee cans for big jobs and never had a problem. "I love the smell of CPES in the morning..."

  33. #33
    Join Date
    Jun 2018
    Location
    Lake Odessa, Mi, USA
    Posts
    73

    Default Re: Penetrating Epoxy kicked off

    Thanks again for all the information. I think it was all about the temperature, who knows how hot it was that day. With the boat being wrapped and it's 95 outside, high humidity and the sun beating down it is really hot on the boat. Our temps have dropped and I did another batch over the weekend with no issues. When I do more and it is warm like that I will keep it cool as many suggested.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •