Rage Ultra Xtra Question

JJH Jimmy

Promoted Users
First I want to say I am a novice. I recently sprayed epoxy primer on my doors of my project and 24hrs later spread a thin coat of rage Ultra Xtra on them. A couple of days later I went to start sanding them and there is a section of the filler that seems a little tacky and I can scratch it pretty easily with my finger nail? It sands ok and doesn't clog 80 grit paper bad but I am wondering if I shouldn't sand it all back off and start over? It is cold here in Michigan but when I sprayed the epoxy the air temp in my shop was 75 degrees and the panel temp was 70 degrees. 24 hrs after spraying I turned the heat down in my shop to 65 degrees and the panel was about 60 degrees when I applied the filler. I have used this filler in the past on this project and never had a problem but it was warmer and more humid than it is now. When i mixed the filler I will add one stripe of hardener for anything up to 4 1/2" puddle for filler and a stripe and a half for 5" to 6" puddle of filler. What are your thoughts. Thank you.
 
Ultra Xtra is designed to have a long working time. In cooler weather it is best used blended with Rage Ultra. Sometimes with any filler, but especially this one in cooler weather if you don't have enough hardener in it, you sometimes get it where it's tacky after it sets up. If it sands ok and doesn't gum and when you are finished you can't scratch it off the epoxy underneath you are ok.
 
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First I want to thank you guys for taking the time to help a novice like myself out. This forum is great!
Ok, I got home and decided to just sand the problem area off and start over. So I sanded it off with my da and 80 grit. In doing so I noticed the epoxy under the filler was soft and I could scratch to bare metal with my finger nail. I then block sanded the other area of the panel that the filler was was good and the epoxy is also soft under it. So I am thinking I should have waited a few days before applying the filler. Lesson learned. My question is will the epoxy eventually cure under the remaining filler on the areas I block sanded or should I strip it back to bare metal and start over. It’s only 2 doors so it not a huge deal but now I am worried about the fenders and hood that I already put in 2k and are ready for color when the weather gets warm. I should add that in areas where no filler was added the epoxy is rock hard.
Thanks again for all the help you guys are great!
 
When it’s 60 degrees I use Rage Ultra. I only use Xtra in the hot summer months.

Don
I saw the chart so I knew the filler took a while to cure at 60 degrees but since I work on my project when I get home from work it was not a big deal to me. I usually wipe filler on one evening the sand the next. I think I will get a can of the regular ultra for the cold months. Truth be told the xtra was setting up too fast on me during the warm months!
 
I put a couple 500w work lights shining on the panel and kept it about 90 degrees for a day and the exposed epoxy is now rock hard like the rest of the door. So for a test I sanded off the filler on a door ding down to epoxy and it is still soft and I could scratch down to metal with my finger nail. I know that epoxy can take weeks or even months to get to full cure so am I safe to assume that this is normal and it will eventually get to full cure? Thank you!
 
In that chart, I don't know what they consider dry, but there is no way 100% Extra could be sanded in 2 1/2 hours at 60°, at least the way I mix it. I personally never use it 100%, even in summer, just don't like the way it sands. 24 hours should have been enough time to apply filler, but temperature and mil thickness will definitely affect the dry time. I had the same problem waiting overnight, applying filler, then sanding with 80#. The 80# just ripped the epoxy off the metal and before stripping it, I called Barry and he convinced me to wait and check it the next day. The next day it was better, but still would not feather well with 80#. Sanding with 180# made all the difference, and feathered much better. I believe it will still cure when covered, (but I've been wrong twice today :)), but it slows it way down. I would strip it (at least those areas) if it still came off the metal easily after 4-5 days as mentioned above. It is not worth the risk, IMO.
 
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Thanks guys! Better safe than sorry. I will strip it back off and give the epoxy a few days to cure before applying filler when the temperature is near the minimum. I appreciate all the help!
 
Like TK I never use the stuff straight. Even in the hottest weather I probably use it 80%Ultra 20% Xtra ( I actually use the Evercoat Edge brand but it is the same stuff). Hot weather you just accept that you will apply it in smaller amounts. And like TK says I don't like how it sands either. I add enough to extend the working time some but not so much as to greatly change how the Ultra sands. The quicker you sand it after it kicks over the better/easier it sands. If you wait a day or more it doesn't sand as well. That's true for all body filler though not just Ultra.
It is nice to use with glaze though. I use it more with that than anything else. Allows you to actually have time to apply the glaze. Glaze in hot weather with no additive like Xtra, you have about 30 seconds from the time you get it mixed. And you have to mix quick. That's where this stuff is great.
 
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