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epoxy compatibility question

PostPosted: Tue Oct 09, 2007 6:18 pm
by nikwax
I think I know the answer to this, and...


I have a lot more Raka epoxy than hardner at this point, and and I'm running low on hardner. Do I have to stick (ha ha) with Raka hardener or will another brand be compatible?

I'd hate to make a mess. But as Raka is on the other side of the country from me, it would make sense to source hardener locally if it would work.

PostPosted: Tue Oct 09, 2007 7:30 pm
by jeepr
I am no expert, but in my opinion stick (haha) with the same manufacturer. I mean another hardener may work, but your taking a heck of a chance. It would suck having to remove a bunch of goo from the trailer. Maybe test some first if you try a different brand.

PostPosted: Tue Oct 09, 2007 7:31 pm
by Miriam C.
:( I bet Doug and Steve F are going to jump in here any minute but my understanding for "some", maybe not all, they make it a system to be used together. I wouldn't mix something I bought as a "system". You might call RAKA and ask. :thumbsup:

PostPosted: Tue Oct 09, 2007 9:58 pm
by doug hodder
I'd think that since you are running low and have to get some anyway...why take the chance on something that might not be compatible?, unless you really have a desire to learn something you didn't have to....If'n it were me...I'd stick with what I know that works. I'm kind of a "don't make work for yourself" type of person. If you do mix...please let us all know how it works out. :thinking: From what I hear...Raka does ship quickly... Doug

PostPosted: Tue Oct 09, 2007 10:10 pm
by madjack
nik, stick with the RAKA...different companies have different formulas for their products...for example, West Systems might be a 5 to 1 formula, while RAKA has a 2 to 1 formula...by the time you experimented around to get a workable formula, you would probably be outta resin anyway...RAKA, sez you can use up to 20% less hardner than called for, it will make the potlife longer....
madjack 8)

Re: epoxy compatibility question

PostPosted: Tue Oct 09, 2007 10:16 pm
by rbeemer
nikwax wrote:I think I know the answer to this, and...


I have a lot more Raka epoxy than hardner at this point, and and I'm running low on hardner. Do I have to stick (ha ha) with Raka hardener or will another brand be compatible?

I'd hate to make a mess. But as Raka is on the other side of the country from me, it would make sense to source hardener locally if it would work.


Have you called these guys. Perfect Surface Northwest Inc
8830 Asheville Highway, Tigard, OR 97223
(503) 968-6162

I did a search and this is what came up

PostPosted: Wed Oct 10, 2007 8:49 am
by nikwax
thanks everyone. I was pretty sure that the right thing to do was to go with the same product.

PostPosted: Wed Oct 10, 2007 1:09 pm
by Alphacarina
I think you can probably go with any brand so long as they have the same 2 to 1 ratio of resin to hardner that Raka uses

I would be very leary of any other combination

Don

PostPosted: Wed Oct 10, 2007 5:35 pm
by angib
madjack wrote:RAKA, sez you can use up to 20% less hardner than called for, it will make the potlife longer....

That's pretty amazing - most epoxy manufacturers would scream at the idea. Poor measuring, and hence wrong mix ratios, is a common cause of epoxy not going off right.

Using one manufacturer's hardener with another manufacturer's resin sounds dangerous to me - some of the hardeners have quite different formulations and ingredients. Epoxy is very different from polyester in this respect (for poly, anything will do!).

Andrew

PostPosted: Wed Oct 10, 2007 10:38 pm
by madjack
angib wrote:
madjack wrote:RAKA, sez you can use up to 20% less hardner than called for, it will make the potlife longer....

That's pretty amazing - most epoxy manufacturers would scream at the idea. Poor measuring, and hence wrong mix ratios, is a common cause of epoxy not going off right.

Using one manufacturer's hardener with another manufacturer's resin sounds dangerous to me - some of the hardeners have quite different formulations and ingredients. Epoxy is very different from polyester in this respect (for poly, anything will do!).

Andrew


RAKA, doesn't recommend adjusting their formulas, just that you can be upto 20%(not enough) on the hardner and it will still work(just not as well)...they don't recommend too much hardner under any circumstance....

FYI...a warning...I am presently working on a new project, using epoxy...while I have messed around abit using polyester, I have never used epoxy before...I had mixed up and used several small batches but was working on 2, 4'x9' panels and being the smart and thrifty fellah that I am, I decided to mix up a LARGE batch(3 quarts, in a 5 quart pot) and pour it out over the two panels and spred...it got so hot so fast that it set fire to the local atmosphere...as I poured it out and attempted to spread it, the mix snotted up on me and I had LARGE and HOT snot globs covering my work pieces...the next day, with 5 hours of sanding, I was back to square one and a valuable lesson learned which was neither smart nor thrifty.............
madjack 8)

PostPosted: Thu Oct 11, 2007 6:13 am
by angib
Yeah, everyone who uses epoxy learns the hard way how fast it can go off! I found starting a collection of half-full mixed pots of epoxy, generally with a stirrer or paint brush bonded into them, embarrassed me into doing better. Ownership of a solid epoxy impression of a roller tray, complete with embedded roller and frame, does wonders too....

Another slip that's waiting for the polyester user switching to epoxy is to not stir the mix thoroughly enough and end up with tacky patches on the job.

It's worth breaking out the little 'puck' of resin that drains to the bottom of the mix pot - the presence, or not, of a sticky ring around the bottom of the puck is a good test of how well the mix has been stirred. I think it would be impossible to get this effect with poly - if some of a pot of poly goes off, it all goes off.

Andrew