2 easy epoxy questions.

[roger1]

First question:

I notice now it says right on the can to let the mixed epoxy induce for 30 minutes prior to use.
I thought it only needed to be induced if it was reduced. Has this now been changed to always do it?

Second question:
When reducing epoxy, do you let it induce first then add the reducer or add the reducer in the initial stir and then let it induce?

 

[form406]

seems with experience guys are inducing 30 mins minimum all the way to over night. personal preference. reduce after induced.

 

[shine]

unreduced i'm leaving overnight . reduced for sealer i'm waiting 30 min or so.

 

[Senile Old Fart]

Do a search on the topic and you will find Barry used to say no induction needed, but has since said induction will give better results.

 

[roger1]

Thanks guys.

I'll induce just since it's not hard to do anyway. And, I'll reduce after induction for sealer.

 

[Barry]

Roger,
We have always known the the epoxy if allowed to induce, sprayed and handled better and a lot of painters that use the epoxy on a day to day basis figured this out long ago.

Reason for the mandate, is we found when used as a top coat like on moldings if the humidity was a certain level or the compressor shooting water in the line, non inducing could shorten the fastness and color could bleach sooner then normal.

The original 30 minute induction was for the epoxy to mate with the urethane reducer.

 

[Bondoskimmer]

so induce period ??

 

[Bob Hollinshead]

that's the recommendation, not a necessity but it does spray better and cure better with some induction time.

 

[strum456]

If the original 30 min induction was for the epoxy to mate with the reducer, does that means the reducer should be added before inducing, not after?

I used to put the reducer in and let it sit, but someone on here said to put the reducer in after inducing the primer. Please advise, Barry.

 

[HomegrownDiesel]

"The original 30 minute induction was for the epoxy to mate with the urethane reducer."
I was reading something into that quote also.

?

 

[Barry]

If the original 30 min induction was for the epoxy to mate with the reducer, does that means the reducer should be added before inducing, not after?

I used to put the reducer in and let it sit, but someone on here said to put the reducer in after inducing the primer. Please advise, Barry.

What we wanted to happen was the epoxy mixed with the activator and then reducer added, stir and let induce.
Then when ready, stir again as it can settle in mixing cup, pour in gun and shoot.

 

[strum456]

Thanks Barry!

 

[chevman]

What we wanted to happen was the epoxy mixed with the activator and then reducer added, stir and let induce.
Then when ready, stir again as it can settle in mixing cup, pour in gun and shoot.

While in a discussion with a kirker user, their tech sheet came into question because it was vague on something, so I called their tech line. While talking with the tech about that epoxy issue, he also mentioned that they recommend reducing epoxy when ever using it wet on wet, even if top coating with 2K primer for better adhesion. I know Barry doesn't require this, but would there be a benifit?

 

[Deleted member 7]

Kirker epoxy and SPI epoxy not the same bird.. There have been plenty of people that have used both.. I have seen many post on other forums as well as the old SPI forum that while they felt the Kirker was fine for metal, they said it was too brittle for plastics and rubbers that we use SPI on also..

From a non chemist view ( me ) the extra reducer would help the product bite into whatever you sprayed it over, but with SPI epoxy, YOU DONT NEED TO REDUCE IT TO SPRAY 2K OR POLY PRIME OVER IT.. I DONT SEE A BENEFIT WITH SPI EPOXY,. HOWEVER I SPEAK ONLY FOR SPI EPOXY!!!!

 

[chevman]

Thanks BK, I was only trying to find the best practice for SPI epoxy. Some things are the same for all epoxies, so just checking.

 

[jeremyb]

Reducing and not reducing depends on how you spray and what film build is before you put 2k or poly down over it.

If you wet it on with a primer gun......you probably need to wait overnight before you apply 2k or poly. But if you lay it on with a 1.4 tip or so, you would be good after an hour or so at 70 degrees, assuming you didn't have excessive build. The epoxy coat still needs to be wet, as to not bridge any of the scratches.......but you want to stay away from excessive build if going over top with a 2k primer or poly primer. Most epoxy primers call for reducer even if being used as a build coat. I think this is where the confusion comes in...

 

[Barry]

Guys, one thing to remember epoxies are all made different and can vary widely in what they do or don't do.

If you are making a an epoxy for a wet on wet sealer.
Making an epoxy of spraying big equipment in the field that never see a garage.
Making an epoxy for sea going boats or oil rigs.

All these epoxies need to be made a certain way, to work in their environment.

If you have six months and thee inches of spi epoxy mixed, leave in painters pail for 6-9 months, when fully cured you will see the toughens and still a little flexibility.
Some epoxies will be brittle after one coat and some warn you not to do 2 or three coats but like I said they are made that way to accomplish certain things and that company would know best how they want it used.

The whole point of this is whatever epoxy you use, follow that manufacturers tech sheet as they know best, what the product will and will not do.

I will never forget, the nasty call I got a year or two ago from someone that used the perfect paint job with another brand all the way through the job, could work but he picked the wrong company and in short he used the epoxy wrong and their clear was not made to be treated that way.