Reducer and Retarder

ffltstn

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Am I understanding this correct? If I want to thin say Epoxy I would mix it with the activator and add reducer. If I wanted to thin it and change the speed at which it dries I use Retarder in place of the reducer? So a retarder will always thin the mixture?

Thanks Guys,
Ken
 
You would not use retarder with epoxy. Never. Retarder is for activated urethane products only. It doesn't need it anyways. Retarder allows a (poly)urethane clear to flow more. Or behave like it does at 75 degrees when it's 95+ degrees. Retarder doesn't affect the cure time of a urethane, it affects the open time which lets a clear flow more or in hot weather not flash off as quickly.

Epoxy can be re-coated without sanding for up to 7 days. It will "cure" enough to put body filler over it after 24 hours @ 70 degrees panel temp, after 48 hours @ 70 degrees panel temp, it can be re-coated with polyester primer.

There really is no need to ever slow down the cure of epoxy. To speed it up you can place your panel in the sun. Even in winter the UV rays will spped the cure up some. Or use a refinish infrared heater.

You only want to thin epoxy when using it as a sealer. Otherwise mix 1:1 to get the full benefit of it.
 
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Just got off phone with Barry and he said his epoxy doesn't need retarder. The one speed activator is designed to work over a variety of temperature ranges so that it can be used for a variety of situations. If it needs to be used as a sealer, reduce with reducer only.
So best advice is not to mess with what the master chemist has formulated.
 
If you want to slow dry time on base use slow or extra slow reducer. For important stuff I let base dry overnight before clearing.
 
I am in central Florida so most of the time it is hot and humid. That's why I'm asking, to know when the time comes. Also so I can estimate what to purchase and have on hand.
 
I live in Arizona at 4400' elevation. That means we get a touch of the 4 seasons here but the summers are hot.
So I tried the Retarder on a final coat of clear to see if it would flow out better.
This is the 3rd coat of clear as sprayed using the Retarder.
Retarder.JPG


Personally, I haven't used it since. I find I can get the same results using the Slow Activator and Slow Reducer.
If you find your are getting too much orange peel in your clear coat applications, there can be a number of reasons for it. Experience and technique can eventually resolve this but for a quick fix the Retarder will definitely help.
 
I live in Arizona at 4400' elevation. That means we get a touch of the 4 seasons here but the summers are hot.
So I tried the Retarder on a final coat of clear to see if it would flow out better.
This is the 3rd coat of clear as sprayed using the Retarder.
View attachment 23411

Personally, I haven't used it since. I find I can get the same results using the Slow Activator and Slow Reducer.
If you find your are getting too much orange peel in your clear coat applications, there can be a number of reasons for it. Experience and technique can eventually resolve this but for a quick fix the Retarder will definitely help.
That’s pretty darn slick!
 
You would not use retarder with epoxy. Never. Retarder is for activated urethane products only. It doesn't need it anyways. Retarder allows a (poly)urethane clear to flow more. Or behave like it does at 75 degrees when it's 95+ degrees. Retarder doesn't affect the cure time of a urethane, it affects the open time which lets a clear flow more or in hot weather not flash off as quickly.

Epoxy can be re-coated without sanding for up to 7 days. It will "cure" enough to put body filler over it after 24 hours @ 70 degrees panel temp, after 48 hours @ 70 degrees panel temp, it can be re-coated with polyester primer.

There really is no need to ever slow down the cure of epoxy. To speed it up you can place your panel in the sun. Even in winter the UV rays will speed the cure up some. Or use a refinish infrared heater.

You only want to thin epoxy when using it as a sealer. Otherwise mix 1:1 to get the full benefit of it.

That is a very easy and clear explanation to the questioned asked.

Well done!
 
I am in central Florida so most of the time it is hot and humid. That's why I'm asking, to know when the time comes. Also so I can estimate what to purchase and have on hand.
If it's warm, SPI 885 and SPI 895 reducers are the best that you can use. 885 is good to 85 degrees or so. 895 is good from 85-100+. If by some chance its 85+ degrees when you are painting, then you can use retarder in your clear at the rate of 1-2 ounces per 32 ounces RTS (ready to spray). That should be more than enough.
 
I looked at the Reducer page, PDF, it does not have temperature ranges listed for various reducers. Is there a list someplace? Thanks
 
Reducer selection isn't just about temperature, the size of the job matters, too. But the clue for SPI reducer is in the last two digits of the part number, 860 is for a one or two panel job at 60°, 870 works at 70° for this, etc. But you could use 870 on a hot day to paint a mirror, or use 885 at 68° degrees to do a complete.
 
Reducer selection isn't just about temperature, the size of the job matters, too. But the clue for SPI reducer is in the last two digits of the part number, 860 is for a one or two panel job at 60°, 870 works at 70° for this, etc. But you could use 870 on a hot day to paint a mirror, or use 885 at 68° degrees to do a complete.
Thank you, much appreciated.
 
Reducer selection isn't just about temperature, the size of the job matters, too. But the clue for SPI reducer is in the last two digits of the part number, 860 is for a one or two panel job at 60°, 870 works at 70° for this, etc. But you could use 870 on a hot day to paint a mirror, or use 885 at 68° degrees to do a complete.
Would you agree that needle size plays a role? The smaller the tip, the slower the activator/reducer. That's one reason the 1.4 is recommended. It makes larger droplets and allows you to use a closer to actual temp additive. Just a thought.
 
Would you agree that needle size plays a role? The smaller the tip, the slower the activator/reducer. That's one reason the 1.4 is recommended. It makes larger droplets and allows you to use a closer to actual temp additive. Just a thought.
I guess so, never really gave that much thought to be honest, but it makes sense.
 
I originally came out with the retarder for 2k primers for bigger jobs in hot areas for the southern states.

I think more is now used to play games with clears than primers.
That and blending agent are two of the best things I have done.

The more you play bench chemist, the better you get. (just my opinion).
 
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