Thinning Epoxy with DNA

OK Lemat your the man for this one.
I have read in several places, including Sways, that epoxy can be thinned with up to 20% DNA (denatured alcohol).
What is your professional opinion about this?

To thin epoxy you need to use a solvent that spread over well before resin set. If some left in resin it reduce mechanical properties. For a lamination i wouldn’t use more than 5%. Xylen better than dna.

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I’ve used both DNA and Xylene to thin epoxy and Xylene is by far better but I’ve been noticing Xylene not being on the shelves of some hardware stores along with some other paint thinners. Guessing governments are making some of this stuff harder to get.

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When I turned that epoxy planer knob, I got a whiff of some solvents (perhaps xylene or Additive F) that were 10 years or more old. Being molded in a glass light bulb did not give them much chance to escape.

I have tried DNA too, it was not life-changing. In some places like California even DNA is getting harder to come by. We use it as cookstove fuel in the sailboat.

Some other options to reduce viscosity are warming the resin side before mixing and working in warmer conditions.

@stoneburner Are you thinking about this for a lamination or bare foam coating or ?

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Yes i can’t find xylene any more. Some use toluen as replacement. Can use methanol if not water in. For sure better to warm or use “real” reactive thinner (diglicidilether base)

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I have used vinegar to thin epoxy resin without any problems. I too have found that if you simply warm it up it will thin the viscosity.

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This response, while directed to Lemat, is also for all who were considerate enough to comment/respond.

I am developing a process for sealing multiple surface types with epoxy. The process would work better with a more fluid sealer than un-thinned epoxy.

Besides being a much nastier solvent (biologically) than DNA, xylene will melt at least one category of surface materials I want to seal.

I only need one thin/more fluid sealer coat (that bonds well with un-thinned epoxy). Can’t think of anything that bonds better/chemically with epoxy than (tack-free) uncured epoxy. Then I move immediately to un-thinned epoxy for laminations or additional epoxy coats.

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Just a thought …
most fibers get a finish to bond well to epoxy, the most common being silan based - maybe have a look at those . Theres a wide range of silan based chemicals, and as I got it these are used as surface agents , thinners , flexibilizers or bonding agents .

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Thanks Jspr.
But this sealing process is not for composite fibers/cloths.
This is for sealing surfaces to which more epoxy will be added or to which composite cloths/fibers will be laminated.

I know what you need if you can use water on yours materials: water base epoxy.
https://www.resoltech.com/en/markets/1010-detail.html
You can diluate it to water consistancy. Best impregnator system i can use. I waterproofing old wood for exterior use, very efficient.

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Very cool product, I was not aware of its existence. Thanks for sharing the link!

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Équivalent from other producer
https://www.boutique-resine-epoxy.fr/en/range-of-epoxy-resin-products/311-waterbased-epoxy-resin-waterbond-sr-1900-hardener-sd-1905.html

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Thanks Lemat.
Those look like a great solution, especially for wood.
Do they have U.S. distributors?
Do you know what mixed viscosity is — couldn’t find it on their site.

Found some U.S. water-based epoxy for concrete/masonry sealing.

What about this product?
https://www.jamestowndistributors.com/product/product-detail/97636

I bet it something équivalent. When thining it’s near water viscosity. Reslotech are sold under other label but don’t know in your country.

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all seriousness aside,now is the time for a little humor,as a straigghtline thinning epoxy with dna made my look skyward and think of how much thinner I have wasted spitting on the ground or on kleenex or washing clothes , i allways thought disrict attornies were used to thin epoxy. … to thin the pox during the plague they used shredded SparRow wax and ex Eileen, well so much for humor,i had to drive my bike off a cliff and break my arm to learn about the relationship between humor and the ulna, isnt that funny… bone? Quick mix up some red pigment and make a couple hearts… tomorrow istwo days after presidents day! love you guuys de mompassant(metaphor for snappy dressers…)

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I never thin Epoxy because I heat it briefly before I mix it. But I have heard that xylene is the agent used if you thin. I have also heard that Xylene is the base/medium for wax solution for Epoxy. ie Additive F.

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I’ve thinned it with DNA, the problem is some DNA is not too pure and has crap in it that will cause fish eyes. Buyer beware. I scientifically measure by adding a cap full when needed.

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I’ve been talking with a guy who makes Bamboo skinned EPS boards, and doesn’t glass them. He said he uses a 50/50 resin/ DNA mix to seal the foam before vacuuming the bamboo. The mix soaks into the foam quite a bit and helps with making the foam more water resistant. He’s been making these boards for a while.
I don’t know if this would work on XPS or foams that are not porous like EPS.

I use Xylene or DNA to thin my resin, but the last several times, I had very bad fish eyes. I think my DNA and Xylene are too old.

For this application those new waterbase epoxy should be excellent. When thinned with water it soak deeply in all kind of porous materials. One use of them is to waterproof steel reinforced concrete builds… good! Time to try again old idea…

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