Epoxy after 7 days

R

Revolver

So I shot 2 coats of epoxy on a quarter sunday before last (9 days ago), but was pulled away from the job before I had a chance to do my filler work. Do I need to sand the epoxy, shoot another coat and then do my filler, or can I sneak by and sand, do filler, then recoat with epoxy? The tech sheet says to sand and recoat after 7 days to apply 2k, but nothing about filler.
 
I agree, I always sand with 120-180 before applying filler. It's to easy to do in comparison to the risks.
 
if within a couple of weeks in my cool dry garage (i cure in the sun) i sand and if it smells fresh i fill, especially if its gonna be buried in more epoxy... if it doesnt have that "fresh" smell i give the area a quick recoat cure and fill... in any case it never hurts to recoat for shure.
 
there's a reason it says 7 days. if your not going to adhere to the rule then why even bother with epoxy in the first place. hack it with 36 and go for it.
 
Just from my experience, but always sand and re-shoot one coat if your out of the 7 day window, its better to be safe then ahh #$@% in a year.

On a side note, I did learn that windshield urethane does not like sticking to the epoxy. I tried it both ways having glass put in on the shop truck the front window was placed with in the 7 day time frame. The rear about 15 days out. About a month later had some really hard rain and leaks were everywhere. Had the glass pulled and it literally poped out no cutting needed. The glass guy was in total loss on why it never stuck to the body. I scuffed the channels re-shot a coat of epoxy scuffed it again then shot a coat of ss in the channel. 2 years later still no issues. My personal lesson was Always scuff the epoxy before doing anything above even if its within the 7 day.
 
shine;22360 said:
there's a reason it says 7 days. if your not going to adhere to the rule then why even bother with epoxy in the first place. hack it with 36 and go for it.
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What He Said!
 
there's a reason it says 7 days. if your not going to adhere to the rule then why even bother with epoxy in the first place. hack it with 36 and go for it.
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36? you refering to me?
the whole reason he is asking is because there is no stated window / rule for filler on epoxy. like i said it never hurts to recoat for sure! one thing for sure if the filler aint bitin the porchdog is!
 
Since I am in the "hack it with 36" club you all may wish to take this with a grain of salt, but my actual experience during dozens of filler over epoxy jobs has shown results that are counter to what might be expected, namely:

1) After 72 hours, I have seen adhesion loss of filler over unsanded SPI epoxy, so after 48 hours it always gets sanded prior to filler.

2) I've never seen adhesion loss when our filler is applied over well sanded SPI epoxy of any age.

As far as I know, the only documented instances of serious adhesion loss over aged, sanded epoxy have occurred with basecoat, and this is the major reason behind the rule that fresh epoxy must be applied over aged epoxy before recoating. My own experience shows that the rule doesn't apply to fillers, at least not the ones we use.

I'd encourage users to test the products they use for themselves, since not all fillers are created equal.
 
I'd like to think we can disagree respectfully with each other, there still might be something to learn or common ground to be found. I personally don't appreciate the insulting tone some posters use when disagreeing with others, but hey, all we can do is control our own behavior, not that of others. That's for the mods to sort out.
 
shine;22398 said:
damn , this place is getting as bad as hr.com. i'll let yall handle it from here on in .
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Now, wait a minute, Shine. Your experience and opinion is highly valued. However, Form is right, there is no hard rule about filler over the epoxy. I quote from the Tech Manual, "The epoxy does not need to be sanded before applying the body filler (up to 7 days)" That tells me, after 7 days you should sand the epoxy and still be able to apply filler (mechanical adhesion).

Another quote from the manual says, "This epoxy does not need to be sanded if it's painted over within 7 days. Always paint or primer over the epoxy within 7 days. After 7days the epoxy should be sanded and recoated with epoxy for best adhesion" (chemical adhesion)

So for the chemical adhesion of paint and primer, the epoxy need to be fresh and for the mechanical adhesion of filler, the epoxy just need to be sanded.

Maybe i'll just call SPI tomorrow and ask them direct. The only reason I didn't in the first place is that I hate to bother them. They seem to be a small company and very busy. Plus, I figured this was covered before and someone could answer the question quickly. Using the search feature can have you reading for hours, without your answer.
 
Revolver, the answer from barry is in my reply above. :cool:

Don't EVER be afraid to call them direct and ask questions. Trust me!
 
Thank you, Jeremy. You were replying with the answer at the same time I was replying.
 
shine;22398 said:
damn , this place is getting as bad as hr.com. i'll let yall handle it from here on in .
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Shine,
You know that's not true. You are one of the many reasons I visit this site and we'd still want to hear from you. On the other hand, just because two days ago was the end of your "take it easy" time (six weeks from your June 4, 2012 surgery) you could ease back into things with a few ankle nibbles instead of going for the throat. Yeah, yeah, I know sitting on my ass makes me cranky too.
 
Bob Heine;22413 said:
Shine,
You know that's not true. You are one of the many reasons I visit this site and we'd still want to hear from you. On the other hand, just because two days ago was the end of your "take it easy" time (six weeks from your June 4, 2012 surgery) you could ease back into things with a few ankle nibbles instead of going for the throat. Yeah, yeah, I know sitting on my ass makes me cranky too.
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I thought.... he was nibbling.:D
 
X2 on hearing all sides on new subjects. But i also appreciate when a previous post is used to answer questions quickly. No sense beating a dead horse.
 
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great info in this post. i love this place. shine, meant to poke a little fun and iron out facts. sorry to annoy you. i know youre still recovering. your info is important to me, as well as it never fails that the guitarist gets annoyed at the slow minded bass player. :) feel better buddy!
 
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