Thinning epoxy

[lrogers]

Can epoxy glue be thinned with denatured alcohol so it can be brushed on as a sealer?

[leehljp]

I can't wait to see the correct replies for this. But I will say that I don't think it is denatured alcohol that does it but rather something else. I can see the cans in my mind but can't remember the name.

Acetone will clean up epoxy but it is not a good thinner.

[cabinetman]

I can't say this is the correct answer, but since the reaction of the amount of catalyst added with the addition of a "thinner" would be total guesswork. The parameters of working time, coverage, and maintaining its chemical state over time becomes an issue with me. The times I've tried to come up with an earth shaking solution to a problem I found using the correct material was best. In situations where that would be needed, I use a sealer that is compatible with the rest of the finish, or suitable for the need.



"I'M NEVER WRONG - BUT I'M NOT ALWAYS RIGHT"

[bigsteel15]

I've used a lot of epoxy glues over the years (not for WW) and would have to answer NO.
The instructions that I've ever seen never talk about thinning the product.
What I would recommend is an epoxy "coating" product if you want to seal something and not glue it. Completely water proof and high impact resistance generally. The problem is the cost of good products is quite high.
We currently use the Devcon line of products.
You can do some reading at www.devcon.com
Lots of good technical info.They have adhesives as well.

[leehljp]

Isn't epoxy basically fiberglass without the fiberglass coth? I know there is a product available that is used to thin the fiberglass mix, or at least clean it up well.

EDITED It is available in many hardware stores where they keep the acetone, thinners etc. It has a name that is more of an acronym than a word/name - something like M???

The reason I remember that it was available is that I almost bought a quart this past spring from my local hardware store in my hometown of 2000 people. IF they have it, surely larger stores in larger towns have it.

[maxparot]

Don't quote me on it but I believe the correct thinner for epoxy is Acetone.

[aksarben1010]

Isn't epoxy basically fiberglass without the fiberglass coth? I know there is a product available that is used to thin the fiberglass mix, or at least clean it up well.
[

Not all epoxy is the same there are many, maybe hundreds, different types and flavors of of. It really depends on the use as to which one to use.

No, epoxy cannot be thinned but you could try might look for a Low Viscosity Epoxy Resin such as a marine resin.

Scott

[greencat]

I don't think you can thin it. The hardner and resin are made for a specific combination. Normally polyester is used with Fiberglass and polyester is less picky about the combination.

[wardprobst]

My experience is that denatured alcohol will wash away epoxy while it is still wet. I use it for cleanup, acetone will work also. Whether the epoxy is thinned or merely distributed more thinly is the question. In any case, I've done it repeatedly on hard rock maple to repair split bridge caps in pianos. It does penetrate and seal when done this way but is way messy. You can buy water thin expoxy from Epotek (sp?) but I tend to stay with West Systems.
DP

[LCHIEN]

Chemically, epoxy adhsives are two-parts, They chemically react when mixed to make some long chain polymers that have great physical strength. When the reaction stops it has achieved maximum strength and is considered cured. When it cures, it creates heat from the reaction. In thin layers you don't realize it.

Oil and water-based paints are one-part emulsions that contain solids and a carrier. The carrier is either oil-based or water-based. They work by application in a thin layer and the carrier evaporates leaving the solids. You can thin them by adding more of the appropriate carriers - volatile hydrocarbons or water. The thinned will be in a thinner layer and runnier, so it will evaporate about the same rate. It does not cure in thick sections and when protected from evaporation, i.e. in a can.

If you try to thin epoxies, my best guess is that it will be runnier, but since epoxy does not cure by evaporation, the evaporating thinner will leave voids and there will be a race as to whether the thinner will evaporate first or the epoxy will cure. I think undesirable things will happen either way, assuming you can find a thinner that mixes.

I think epoxy viscosity can be forumalated into the product, there are epoxies that cure in deep sections ( a property of epoxies) and controlling the viscosity affects the void filling properties.

When you guys mention having heard of "thinners" for epoxy I think the use is for cleanup of overruns (while still uncured), not a viscosity reducing agent.

[JR]

I read a Fine Woodworking article recently about a finish for outdoor furniture. In it they brushed on an epoxy "primer" then finished with marine varnish.

The epoxy is called Smith & Co MultiWoodPrime (Clear Penetrating Epoxy Sealer). It is available at www.jamestowndistributors.com

HTH,
JR

[leehljp]

This has interested me and I have been doing some research. There is a thinner on the market and I do forget its name. I almost bought some last spring while I was at my home in MS. It had a name with initials on it like MS?? but I just discovered that MSDS stands for "Material Safety Data Sheet".

The thinner that is offered, as best I can find on the internet, is used for clean up, not actually thinning. There are some suggestions on line for thinning including heating the resin some. In some, as you (Larry) stated, DNA works in some situations, heating in others, and small amounts of other thinner in other situations.

IN pen turning, we are always looking for new and different finishes, as stabilizers in wood pen blanks and as pen blanks themselves. Because of this wide range of need, it has been discussed on the pen turner's forum often. But the thinning has only been mentioned. It was there (and I cannot find the discussion now) that the thinner was mentioned and I started looking for it last spring.

For wood pen blanks, epoxy has been discussed and used on occasion in pressure tanks under vacuum ( -20 to -28) and then under pressure (25 to 50 PSI). Ideally, thin epoxy that cures in 24 hours would be better than using urethanes in that situation. Thin is better because in a vac, the thinner allows for quicker release of the bubbles from the wood and the pressure drives the epoxy into the cells of the wood.

In this case, epoxy is used as a solidifier not as a finish, so appearances are not as critical. We also use plexiglass (disolved in acetone), PR resin, and urethanes.

[gonesailing]

As has been pointed out, there are a lot of different epoxies, and you would probably be better off getting one that is specifically for the job you want to do.

I think that most epoxies can be thinned with acetone, but I also suspectg that you might be disapointed in the results. Epoxies are pretty sensitive to curing conditions, that is temperature and humidity and variations during the curing period. My experience is that it will eventually cure under almost any condition, but not with the strength that you had hoped for.

I have used West Epoxy as a sealer, works very well if you use the slow hardener.

Mike L

[steve_ma]

I have been working with epoxy for a couple yrs now building boats. Simple answer is you dont thin epoxy. There is a wealth of information on the System 3 website.
I brush epoxy on all the time. Its great to use as a sealer for outdoor furniture, but it still needs to overcoated with something for UV protection. As pointed out however, it aint cheap....

[lrogers]

Thanks for the info guys. Not what I really wanted to hear, but you may have saved me from a messy mistake. Back to "normal" finishing methods.