Epoxy/activator separation

D

DWinTX

Member
Hey guys,

I'm working on my 70 Corvette. Bought some black epoxy for the engine bay, sprayed it last weekend, and that worked out well. This weekend I'm spraying white epoxy on the body. A couple hours ago I mixed the epoxy and activator to let it induce overnight as I've seen suggested here. I stirred the epoxy real well with stir sticks before mixing. There was no "sludge" left on the bottom. I also mixed the epoxy and activator really well before covering in the pails.

I just went out to close up the shop and the epoxy and activator are separating as you can see in the pic. This didn't happen with the black I sprayed last weekend. I did notice that the activator that came with the white was kind of yellowish, but it was a different part number than what came with the black, so I just thought that's just the way it was.

Is this normal or is something wrong?
 

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First I have heard that there is more than one epoxy activator. Post a pic of the label. Epoxy activator is 6700.

Don
 
My white epoxy separated like that also and was a tinge yellow. Just stir it when ever you have a chance and especially before spraying.
 
Sprint, you're probably right, one is a quart and one a gallon. 6700-1 and 6700-4. So I guess it's the same stuff.

So if it separates, is it still inducing? Or do I need to mix it up tomorrow morning and let it sit for a while?
 
Let it sit overnight, stir good before you use it. It is still good. It will be just a little thicker but it's ok. Yes it is still inducing. I do this occasionally.
 
I stirred them all up again last night before I went to bed. Got up this morning and found that they had separated again, but at different rates. Two of them separated quite a bit and two others, not much, as you can see in the pic below. Strange.

I just want to make sure the product is OK. I don't want to have to sand 3 layers of epoxy off the whole car. Had to sand it to fiberglass already, and will have to block sand build primer after I get it on. That's enough sanding for me.

Hey 68 Coronet, I like your car. I also have a 68 Coronet R/T. 440/727, B5 blue with a white interior and white vinyl top. Stripped down to the shell and may be the next car I do. I also have a 64 Belvedere 383/4-speed. Can't decide which to do next. :)

Yeah, I'm confused about the inducing too. The can says 30 minutes, I've seen some posts say 4 hours, and some overnight. I did it overnight this time because I wanted to get started spraying early. It's hot here.
 

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ok all your seeing is the white pigment settle. white is heavier than black and will settle out more. this will happen with anything that is reduced and left to sit. base, single stage, primer, etc. stir it up and spray it. there is nothing wrong with it. the epoxy activator will be yellowish and it will get worse as it ages. it doesnt mean anything and works just the same whether its clear or dark red/amber. also, the epoxy doesnt need to be induced at all even though it says so on the can. many years ago the spi epoxy claim to fame is that it didnt need any induction then suddenly the sticker started showing up on the can to do it. its only for sprayability. it doesnt have any effect on the curing. i rarely let my epoxy induce. i mix it then spray it 5 min later. the induction just lets a small amt of the alcohol in the epoxy flash off so it doesnt crater as easy when its sprayed wet. i personally have never noticed a spray difference if i do it right away or let it sit for hours.
 
Got my first coat on. Went pretty well for my first time, but I've got 4 or 5 areas where something went wrong. It looks mottled. Jim, is this what you meant by cratering? This is the worst one by far, the others are fairly minor. Did I spray it too thick, or is something else wrong? What do I do about it? I have two more coats to go. Can I spray over it and then sand smooth later? Do I need to stop and sand before the next coat?
 

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Yep thats what i was talking about. Its no issue. As texas said keep spraying. You can sand it smooth later if you need to
 
Jim C said:
. also, the epoxy doesnt need to be induced at all even though it says so on the can. many years ago the spi epoxy claim to fame is that it didnt need any induction then suddenly the sticker started showing up on the can to do it. its only for sprayability. it doesnt have any effect on the curing. i rarely let my epoxy induce. i mix it then spray it 5 min later. the induction just lets a small amt of the alcohol in the epoxy flash off so it doesnt crater as easy when its sprayed wet. i personally have never noticed a spray difference if i do it right away or let it sit for hours.
Click to expand...

Maybe it was an old post, but I read here a comment from Barry regarding induction....as memory serves....the post was about UV fading and Barry mentioned that a longer induction helps with UV stability/durability BUT 4 hours pretty much maxed out the benefits.

My guess is the overnight crowd just finds it as a convienient way to pass 4 hours and then spray in the AM when conditions are often more favorable.


Edit : http://www.spiuserforum.com/index.php?threads/black-epoxy-topcoat.5362/
 
DWinTX said:
I stirred them all up again last night before I went to bed. Got up this morning and found that they had separated again, but at different rates. Two of them separated quite a bit and two others, not much, as you can see in the pic below. Strange.

I just want to make sure the product is OK. I don't want to have to sand 3 layers of epoxy off the whole car. Had to sand it to fiberglass already, and will have to block sand build primer after I get it on. That's enough sanding for me.

Hey 68 Coronet, I like your car. I also have a 68 Coronet R/T. 440/727, B5 blue with a white interior and white vinyl top. Stripped down to the shell and may be the next car I do. I also have a 64 Belvedere 383/4-speed. Can't decide which to do next. :)

Yeah, I'm confused about the inducing too. The can says 30 minutes, I've seen some posts say 4 hours, and some overnight. I did it overnight this time because I wanted to get started spraying early. It's hot here.
Click to expand...
Sounds like a good problem to have - deciding between two Mopars.
 
HoosierDaddy said:
Maybe it was an old post, but I read here a comment from Barry regarding induction....as memory serves....the post was about UV fading and Barry mentioned that a longer induction helps with UV stability/durability BUT 4 hours pretty much maxed out the benefits.

My guess is the overnight crowd just finds it as a convienient way to pass 4 hours and then spray in the AM when conditions are often more favorable.


Edit : http://www.spiuserforum.com/index.php?threads/black-epoxy-topcoat.5362/
Click to expand...


That was just for the black epoxy. If memory is correct the black is the only color that has the UV additives in it. Lots of people are just leaving frames in the black epoxy. The UV is supposed to help prevent chalking so common in black primers that are not topcoated.
 
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