SP106 Eposy Resin

[jneale]

Not having much luck with this when coating bare plywood. I've done all it says in the fact sheet re preparation etc, but the surface separates into meniscus globules after application. I Have tried warming the mix etc, to give it more fluidity, but it still too thick to fully absorb into the wood. Big problem when it goes wrong as its a bugger to sand it flat again. I was thinking of thinning it further with acetone, but anyone got any better ideas.

 

[Poignard]

Are you degreasing the surface with acetone before you apply the epoxy?

 

[prv]

Don't have anything to add re causes, except to say that I've never had this problem with West epoxy, but I have read a couple of well-informed articles which advise against thinning epoxy with solvents.

Pete

 

[TQA]

You have something on the plywood surface that is causing your epoxy to fish eye.

Try wiping twice with acetone then do a test patch.

Do be aware that you can have the same problem if you put on a second coat, Wipe with acetone first.

 

[pcatterall]

No problems when I did this. I did thin the first coat as per instructions but not with acetone ( can't remember what I was told to use)

 

[macd]

Not having much luck with this when coating bare plywood. I've done all it says in the fact sheet re preparation etc, but the surface separates into meniscus globules after application. I Have tried warming the mix etc, to give it more fluidity, but it still too thick to fully absorb into the wood. Big problem when it goes wrong as its a bugger to sand it flat again. I was thinking of thinning it further with acetone, but anyone got any better ideas.

For making epoxy resin less viscous, see this:
www.epoxyworks.com/14/pdf/ThinningEpoxy.pdf

From the sound of it, though, your beading problem is some sort of contamination.

Problems applying second coats are usually due to 'amine blush', a waxy deposit to which some epoxies (notably West) are prone when cured in high humidity. This is usually scrubbed off with water.

 

[jneale]

Thanks to all respondents ... Will have another go when weather gets better

 

[Boathook]

Never had this problem myself but as others have said it seems like contamination. This would also possibly apply if the wood has been treated with some anti-rot stuff, especially if it was oil based.

 

[DownWest]

One of our OZ posters recommends meths for thinning. Personally I use Resoltech Re1010 for coating. Very easy and sets smooth, no amin blush.
Did you warm the wood first? Helps the flow. But it does sound like contamination.
A

 

[Wakatere]

I think SP specify 320 for coating rather than 106.
I agree with others about surface contamination, though.

Good luck
Charles

 

[Jenaline IV]

106 coats perfectly fine on plywood. I have used it for such an application on several boats with different types of plywood, none have done what you describe.

I can only think of a treatment in the plywood? Oil natural or otherwise? Or the epoxy itself

 

[oldsaltoz]

Between now and warmer weather I would be sanding all the epoxy off to remove the contamination.

The epoxy you have already applied will not have penetrated due to the contaminant so must be removed or you will be wasting materials and time.

When you finished sanding, wipe down with white cotton rags and Acetone.

One of the products you can use to thin epoxy resin is denatures Alcohol, that's Methylated Spirits to most of us.

But most fast evaporating products will work but will cost a lot more.

The exposed end grain on the edges will take 4 or 5 times as much as the surface veneer, so keep wetting the edges till that will take no more. Apply wet on tacky to avoid sanding between coats.

Always clean the epoxy coating that has cured 'before' sanding, or you will just be spreading and contamination.

Good luck.