Before Thinning Epoxy Read This

[Bob La Londe]

I was using some epoxy resin today for a nonstandard application and I was thinking it might flow out a little smoother if it was thinned a bit. This was one of the best articles I found on the subject.

Before thinning epoxy read this article.

http://www.seqair.com/skunkworks/Glues/WestSystem/Thinning/Thinning.html

It was the very first search result I saw. Basically says that conventional thinning is a bad idea. Just 5% chemical thinner can reduce strength by 35%. It does go onto to mention bringing up the temperature of your base material as a good alternative. Where I live that means set it outside for a minute in the summer time.

 

[Bob_VT]

Re: Before Thinning Epoxy Read This

This is a great article to read for people who are using epoxy on any wood. I will keep this stuck for a few days up at the top of the Restoration section

 

[sprintst]

Re: Before Thinning Epoxy Read This

So I'm not crazy...though it probably could be debated.

I posted before that I thought that the wood heated in the sun before epoxying had deeper penetration of the epoxy than the cold sheet in my garage.

Good to know for next time

 

[arimatation]

Re: Before Thinning Epoxy Read This

I worked for my Brother in law's ROV "Remote Operated Underwater Vehicle company in San Diego.

We did a lot of potting parts/assemblies, and wires with epoxy. We used heat guns for getting trapped air to come to the surface as well as to make the epoxy flow better. I am glad I learned some of the tricks because the boat I bought will need some glass repairs. Some of the vehicles go to 1500 meters. I was surprised that epoxy was able to withstand those pressures. But it is pretty tough stuff. Last time I talked to him they were working on a 3000 meter system.

That was a good article. I will probably use West System products. Thanks for posting it.

 

[out 2 launch]

Re: Before Thinning Epoxy Read This

This article explains what happens to West System epoxy when it is thinned either by heating the components or adding solvent to the mixture.

I have used the West System products for close to twenty years, in boat building and repair, and consider it an excellent product. However, the test results were performed on West System 105/206 resin and do not necessarily suggest that the same results apply to other brands.

 

[Yacht Dr.]

Re: Before Thinning Epoxy Read This

Hello m8s..

Thinning of epoxy or poly is a standard when working with wood.

Just depends on your application...

Simply put.. you have a Wood boat.. with a Spar thats like 45-60 foot... and you have a "weak" spot in that spar. well..you cant just fill with epoxy now can you.. you have to have the tree spar doing what it was ment to do. cant just fill it with epoxy.

"" 2) Adhesion in all but the highest density wood is not enhanced by deep penetration of the glue into the wood. Research performed at the Forest Products Laboratory showed that adhesion to birch was increased slightly by using thinned epoxy. In lower density wood species like Sitka spruce or Douglas fir, the weak link is the cross grain strength of the wood. It does not matter if the epoxy penetrates l/4" into the wood or 0.005". The strength of the wood, the amount of surface area and the adhesive ability of the glue determine the strength of a glue joint. Most types of wood glue do not penetrate deeply, yet, if used properly, they can exceed the grain strength. Epoxy is no exception. ""

THis is only disclaimer.. basically this par suggests that thinning your epoxy has some merrits ( only on the hardest of woods..like your going to buy some mohog or redheart for your stringers ? ).

guys..you must thin your epoxy to penitrait ( for adhestion perposes ) your raw wood that you use. were not talking remakind a spar..or slap some epox putty in a stringer void. Yes .. your timber that you use for stringers or bulks shoud be cut in the proper way of grain..and be treated b4 any construct applications.

I would not recommend " heating " your epoxy product at all.. use it at the temps ( and the substrait temps ) directed by manufacture..

just my 2C

YD.

 

[piper_chuck]

Re: Before Thinning Epoxy Read This

This article explains what happens to West System epoxy when it is thinned either by heating the components or adding solvent to the mixture.

I have used the West System products for close to twenty years, in boat building and repair, and consider it an excellent product. However, the test results were performed on West System 105/206 resin and do not necessarily suggest that the same results apply to other brands.

Are you suggesting that other epoxies are chemically different enough that the test results are totally invalid on anything but the specific resin tested?

 

[Don Hansen]

Re: Before Thinning Epoxy Read This

I’ve read everything and still wonder if it might work. For one, I’m using new wood so I’m not trying to repair or add strength to it. Second nothing was said about applying multiple coats of the resin mix, which should fill in any shrinkage that might occur. Since the piece of wood I’m replacing, the mount for the gas tank, is easy to get at, I think I’m going to give it a try and see what happens.

Don Hansen

 

[ondarvr]

Re: Before Thinning Epoxy Read This

Old post, it will most likely be closed, but even 3 years later thinning epoxy is still a bad idea.

 

[jigngrub]

Re: Before Thinning Epoxy Read This

This old Chestnut again?

You should start your own thread DH.