Epoxy sealer over 6 month old epoxy?

coby74

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I have body work complete and two coats of epoxy over 180 grit sitting for 6 months. When Im ready to do my final sanding do I sand with 320 then 600 and then epoxy sealer before base? Or do I have to 180 the cured epoxy and apply unreduced epoxy before epoxy sealer?
 
You can reduce the epoxy to 1.1.25 max
Sand the old with 180.
1.1.25 should cover in one coat. If not, do two coats.
Thanks Barry, but I think I'm missing something I thought reduce epoxy had to be applied over 320 or finer grit?
 
Actually Barry was referring to 1:1:25%. 1 part epoxy, 1 part activator, then 25% of the previous two. Example (not for you Don of course:)) 10 ounces (1) +10 ounces (1) = 20 ounces + 5 ounces (25%).
 
Actually Barry was referring to 1:1:25%. 1 part epoxy, 1 part activator, then 25% of the previous two. Example (not for you Don of course:)) 10 ounces (1) +10 ounces (1) = 20 ounces + 5 ounces (25%).
Well I’ll take your word for it. I read it 1 1 .25 so a 12.5% reduction. :)

Same as 1 1 1 is a 50% reduction. Or at least I thought it was ;). Now you have me doubting myself….

Don
 
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25% reduction can be expressed as 1 : 1: 1/2 (don't add the sum) or 1:1:25% (add the sum). I think Barry's post was a typo. I'm probably just confusing things further.:)
 
Well I’ll take your word for it. I read it 1 1 .25 so a 12.5% reduction. :)

Same as 1 1 1 is a 50% reduction. Or at least I thought it was ;). Now you have me doubting myself….

Don
Since epoxy mixes 1:1 with hardener, the .25 is the amount of reducer as Chris stated. Otherwise you would be mixing it 1 part epoxy with 1.25 parts of hardener.
 
Since epoxy mixes 1:1 with hardener, the .25 is the amount of reducer as Chris stated. Otherwise you would be mixing it 1 part epoxy with 1.25 parts of hardener.
Understood. Just assumed it was the volume of reducer, not the percentage reduction. It’s really unclear to me at least. I know the rest of you are a helluva lot smarter than me. Hopefully @Barry can clarify….

Don
 
Hopefully I have this written out correctly. Regardless, it will either help clarify or totally confuse. :rolleyes:

Mixing ratios always begin with the product you are applying, followed by the recommend amount of hardener, activator or reducer as stated on the product can.
1:1 - in this case it is an equal amount of each. Example 1 gallon of base coat plus 1 gallon of reducer. 100%
2:1 - Here we see that you put twice as much product as you do additive. Hence 2 gallons of base coat to 1 gallon of reducer. 50%
4:1 - Now we are at 4 times the product to the additive. Hence 4 gallons of base coat to 1 gallon of reducer. 25%

When dealing with 2k (two component) products, you will have the amount of product first and the activator/hardener second.
Example: Build Primer may be 4:1 which means 1gallon of product plus 1 quart of activator.

If reducer is also needed the ratio of reducer will be in relation to the total volume of the mixed product. Again using the Build Primer as an example: 4:1:1
Which would be 1 gallon of primer plus 1 quart of activator mixed is 5 quarts (160 ounces) to which you would add 1 quart of reducer thus giving you a 20% reduction.

When dealing with Epoxy Primer you have equal amounts of Product and Hardener hence 1:1. If the amount of reducer is given as 1:1:1 your reduction is 50%. 1:1:.5 would = 25% 1:1:.25 would be 12.5%
 
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Hopefully I have this written out correctly. Regardless, it will either help clarify or totally confuse. :rolleyes:

Mixing ratios always begin with the product you are applying, followed by the recommend amount of hardener, activator or reducer as stated on the product can.
1:1 - in this case it is an equal amount of each. Example 1 gallon of base coat plus 1 gallon of reducer. 100%
2:1 - Here we see that you put twice as much product as you do additive. Hence 2 gallons of base coat to 1 gallon of reducer. 50%
4:1 - Now we are at 4 times the product to the additive. Hence 4 gallons of base coat to 1 gallon of reducer. 25%

When dealing with 2k (two component) products, you will have the amount of product first and the activator/hardener second.
Example: Build Primer may be 4:1 which means 1gallon of product plus 1 quart of activator.

If reducer is also needed the ratio of reducer will be in relation to the total volume of the mixed product. Again using the Build Primer as an example: 4:1:1
Which would be 1 gallon of primer plus 1 quart of activator mixed is 5 quarts (160 ounces) to which you would add 1 quart of reducer thus giving you a 20% reduction.

When dealing with Epoxy Primer you have equal amounts of Product and Hardener hence 1:1. If the amount of reducer is given as 1:1:1 your reduction is 50%. 1:1:.5 would = 25% 1:1:.25 would be 12.5%
Which is exactly what I said, 12.5% and iI was called out for it and told it is 25%. :). Hopefullly Barry will clarify since it was a little confusing the way he stuck in all those decimal points…
 
Thanks guys for the help, math was never my favorite subject. The part I'm still not sure about is the sanding. I thought after sanding the cured epoxy with 600 I could spray reduced epoxy sealer then base. The way I understand it, sand the cured epoxy with 180 then 1 or 2 coats of reduced epoxy then base. As the panels sit now in two coats of unreduced epoxy the 180 scratches are still showing, so I don't think reduced would cover them. I think I'm going to call Mr. Barry again.
 
The fresh epoxy has a 7 day window for top coating. Personally, I would do now as you originally thought and wet sand with 320 and then 600, clean and shoot your base.

I believe the idea is to get a chemical bond between the epoxy sealer coat and the base. Not sure about all that, but I have done the above and never had any issues as long as I was in the recoat window.

Hopefully, Barry or one of the pros will verify this.
 
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