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reducing spi epoxy by 20 percent as a sealer

#1
Does anyone have a schematic or can explain how to reduce epoxy by 20 percent as a sealer, I know this sounds elementary but I have never reduced epoxy or primer by such a percent. All the mixing cups I have only have 10-50% on ratios 2:1 and above and the epoxy is a 1:1 ratio but doesn't have a column for a 10-20 reduction to perform this process. Also when it comes to using a urethane reducer for this can you use any urethane reducer or is any particular mid grade reducer preferred?Thanks in advance
 
#2
Don’t forget that along with all the mixing scales on your cup there is also an ounce scale. Look at that and do the math . Once you have how much mixed your going to use then turn the cup around and look at how many ounces you have. 1 quart is 32 ounces so 20% of that is about 6.5 ounces
 
#3
Thanks Dave, so it looks like using the 1:1 at 4 will be 16 ounces so 20% of that would be about 3.5 ounces. So, if this sounds about the way to do it I will just use a separate cup to add the ounces in there. Can you or some confirm that I am correct and not assuming, I would hate to have think I mixed it correctly and stuff starts peeling off or not sticking
 
#4
A few percent off either way is not going to make a difference.
Usually 1:1:1 works well for me and is not much different than 20%,
It makes it easy to measure.
 
#6
1:1:1 is way different than 20%, imo. Around here, 25% is standard for sealer, which is simply 2:2:1

Some common ratios for epoxy:

5:5:1 = 10%
2:2:1= 25%
1:1:1 = 50%
 
#7
1:1:1 is way different than 20%, imo. Around here, 25% is standard for sealer, which is simply 2:2:1

Some common ratios for epoxy:

5:5:1 = 10%
2:2:1= 25%
1:1:1 = 50%
okay , almost got the complete understanding these cups that I have only have 1:1 only and as far as the spi epoxy it's a1:1 ratio, cool no problem. but where do I find that 25% using this column? remember I'm have never reduced this way before. Can you explain the 2:2:1 as its it relates to the cup, here's a pic of the cups I have.
 
#9
here's the way I do it......say I've mixed my epoxy 1:1 and I turn the cup around and it says I'm at the 20 ounce mark, 20% of that is 4 ounces. So I add my reducer until it comes up to the 24 ounce mark.....20+4=24. No need to use a separate cup. Actually if the mixing ratio scale is confusing you then just use the ounce scale, may require some math....4ounces + 4ounces + 4 ounces is your 1:1:1 ( I think ? pretty sure).
 
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#10
the 2:2:1.....say you want 10 ounces total, 4oz +4oz + 2oz.....The "1" is going to be half of what ever the "2" is.......Ha ! it's clear in my mind but I'm sure that last part is confusing as hell the way I worded it. Math is way easier in my head than on paper !
 
#12
the 2:2:1.....say you want 10 ounces total, 4oz +4oz + 2oz.....The "1" is going to be half of what ever the "2" is.......Ha ! it's clear in my mind but I'm sure that last part is confusing as hell the way I worded it. Math is way easier in my head than on paper !
Ok Dave , I got it now I just needed to some to explain it to me this way
 
#13
Dave, you nailed it, I text Barry earlier and he said the exact same way. Use the 1:1, turn cup around to ounce scale x.25 ...add that number to total oz... your right no need for extra cup
 
#14
I use 20 % reduction and just take my mixed number of ounces multiplied by .2. So 10 oz times .2 is 2 ounces of reducer. 20 oz times .2 is 4 ounces of reducer. Simple math that even I can do in my head will I mix.
 

Chris_Hamilton

Trying to be the best me, I can be
#15
I do like Brad does, but you can express 20% reduction as 5:5:2

If you have trouble mixing something that is expressed as a percentage remeber that the percentage is always based off the cumulative total of the ingredients in front of the percentage. 5 parts epoxy +5 parts activator = 10 parts. 20% of 10 parts is 2 parts. If your mix ratio was 2:1:25% it would be 2 parts + 1 part = 3 parts 25% of 3 parts would be 0.75 parts. Example for that ratio in volume would be 16oz to 8 oz (24oz) 25% of 24oz would be 6 oz. So your mix would be 16oz to 8oz to 6oz (2:1:25%)
 
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#16
Thanks chris & Brad, I just have never reduced Or sprayed epoxy as a sealer. I just needed someone to break it down as everyone has so that I can understand it. Yep ... if you mix this S the wrong way you screwed buddy. You guys have definitely helped me understand what I’m doing. Kudos
 
#17
What’s you all take on polyester primer vs regular 2k over body filler on top of epoxy. I am blocking and filling low spots on front cap of 72 C10. I guess the real question is will 2k primer hold up just as good vs polyester primer and then seal it, with 25% reducer. I just don’t want to spray polyester if I don’t need it, also I would have to buy another guy with bigger tip. I Just want a good solid foundation. I found out the hard way that 2K over bare will crack and lift so I took if off and sprayed epoxy first!
 
#19
ok, been block sanding bodyfiller got a few more areas, I’m working hard to get the low spots out. So I posted a pic, I plan to block everything smooth, reply epoxy bc I burned thru metal in some areas.then I will shoot 2k, block that and seal in epoxy. IF the weather allows me to. How this sound? Also what sand grit do I need to proceed thru so I don’t have sand scratches
 

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