Thinning epoxy for brushing on wood

[riggerman]

I have heard that some epoxyies can be thinned down with rubbing alcohol for brushing on to wood has anyone tried thinning down west systems epoxy or NHP 3hour epoxy with rubbing alcohol ? Would the thinning ratio of 50 /50 sound right ? Regards Andris Golts.

 

[Ray Barnes]

I took this from the West Systems site.

Thinning Epoxy

There are epoxy-based products specifically designed to penetrate and reinforce rotted wood. These products, basically an epoxy thinned with solvents, do a good job of penetrating wood. But the solvents compromise the strength and moisture barrier properties of the epoxy. WEST SYSTEM epoxy can be thinned with solvents for greater penetration, but not without the same compromises in strength and moisture resistance. Acetone, toluene or MEK have been used to thin WEST SYSTEM epoxy and duplicate these penetrating epoxies with about the same effectiveness. If you chose to thin the epoxy, keep in mind that the strength and moisture protection of the epoxy are lost in proportion to the amount of solvent added.

There is a better solution to get good penetration without losing strength or moisture resistance. We recommend moderate heating of the repair area and the epoxy with a heat gun or heat lamp. The epoxy will have a lower viscosity and penetrate more deeply when it is warmed and contacts the warmed wood cavities and pores. Although the working life of the epoxy will be considerable shortened, slower hardeners (206, 207, 209) will have a longer working life and should penetrate more than 205 Hardener before they begin to gel. When the epoxy cures it will retain all of its strength and effectiveness as a moisture barrier, which we feel more than offsets any advantages gained by adding solvents to the epoxy.

 

[oldlugs]

I have heard that some epoxyies can be thinned down with rubbing alcohol for brushing on to wood has anyone tried thinning down west systems epoxy or NHP 3hour epoxy with rubbing alcohol ? Would the thinning ratio of 50 /50 sound right ? Regards Andris Golts.

Regular rubbing alcohol contains too much water; it works, but don't use it. Denatured alcohol (sold as shellac thinner) works much better. 50/50 or even thinner is about what I've used. Seems to work well.

Duane

 

[Chris Wood]

Instead of going through all the trouble of thinning try this stuff.

http://www.systemthree.com/p_clear_coat.asp

you can get it here http://www.woodcraft.com/family.aspx?familyid=4669

they are the cheapest i have found.

chris

 

[waltr]

Why don't you try MAS epoxy.

It's much better than West for wood sealing because it's already thinner.

I used it to build and seal my Whiplash instead of West.

I purchased the MAS from Brian Blazer.

Great stuff. Try it,You'll like it!

 

[Darin Jordan]

Why don't you try MAS epoxy.It's much better than West for wood sealing because it's already thinner.

I used it to build and seal my Whiplash instead of West.

I purchased the MAS from Brian Blazer.

Great stuff. Try it,You'll like it!

I actually just did this this week on a project I'm working on... MAS "FLAG" epoxy and slow hardener, mixed 2:1, then I thinned it with about 30% or so of Acetone...

I'm still playing with the application method, but this time I brushed it on with a foam brush, let it sit for about 10-minutes, then wiped off the excess...

On the bottom, I put on a second coat, but left this unwiped... Came out OK... Would like to find a way to have it level out better and be glossy smooth, but it's not too bad...

 

[piper_chuck]

I've had good results mixing up slow cure epoxy, warming the wood with a heat gun, applying the epoxy and then hitting it with the heat gun again. The heat thins it to the point where it smooths out, and any excess can either run off, or be redirected to another spot. The research I read from West Systems convinced me to not thin with acetone, alcohol, or any other solvent. The issues introduced by solvents include potential curing problems, porosity in the cured epoxy, softer cure, and potential cracking.

 

[Mike Hughes]

I've had good results mixing up slow cure epoxy, warming the wood with a heat gun, applying the epoxy and then hitting it with the heat gun again. The heat thins it to the point where it smooths out, and any excess can either run off, or be redirected to another spot. The research I read from West Systems convinced me to not thin with acetone, alcohol, or any other solvent. The issues introduced by solvents include potential curing problems, porosity in the cured epoxy, softer cure, and potential cracking.

My sentiments exactly. I would add, if you would like to save weight you can scrape off the epoxy after it soaks into the wood and put it back in the cup. This way there little wasted epoxy. Just enough to do the job. You wipe the piece down with paper towels after you are done.

Mike

 

[dr gary turner]

Just use your wife's hair drier and it will be like water. Brush the West Systems on, heat with the drier and use a rubber spatula to wipe the excess off. Great surface that can be sanded and the glue penetrates the wood for a great seal. Doc