What are the benifits of epoxy only (no 2k)

I know for a fact that he was hosing Turbo on my car with a 2.2 tip. So, at some point, it will shrink. I doubt anyone that takes advice from this site will ever see it though. I have taken a liking to the all epoxy method mostly because I can put it on bare metal or put filler over it with no added steps. All epoxy doesn't work for me so well in the winter though.
 
orangejuiced86;9286 said:
Now all of a sudden 2k is just acceptable? Has anyone used SPI 2k primer, applied it per instructions and seen shrinkage?

When I talked with barry off this site, he says his primer will fill 80grit scratches, no issued(although I prime on 150).

I'm not a big fan of assumptions, so I want to know who has HAD problems with SPI 2k and if you did, is it becasue you abused it(heavy coats and not enough flashtime)

Honest answers please.
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You misread my post. I was answering his question as to whether epoxy and 2k with more epoxy is equal to straight epoxy and the answer has to be no. Things different are not the same.
But doing it the way he said is perfectly acceptable (read: proper, right, okay, normal). Certainly not saying using 2k primer is substandard workmanship. If that was the case I wouldn't have a gallon in my cabinet. LOL
 
i just do things different. i see no reason to sandwich 2k primer or polyester between epoxy. i'm not in a hurry. dont do collision work, dont get all worked up about how something sands. there is nothing wrong with barry's primers but i wont use other brands on my tractor. everybody has a system. mine just happens to be epoxy only.
 
The only problem with using 2K primer is it's use. What I mean is that it sprays easy and APPEARS to cure immediatly. People believe that once they can sand it, it is cured and will not be a problem. They think that they can spray it as heavy as they want and it will be fine. If you lay any 2K primer on too heavy, Barry's or someone elses, and then think it won't shrink, you will have problems. Primer is not body filler, and should not be used that way.

Primer is fine for lilling sanding scratches and minor imperfections. If you can do it with 2 or maybe even 3 normal coats then fine. If you think it will take much more than that, or if you are in a hurry, then you need to consider another product, or process.

The collision shop that I work at had some serious issues last summer with shrinkage of primer. The problem was because of the techs using it as a last coat of filler and then using the wrong reducer to speed things up on top of that. The stuff would dry so they could sand it and send it to paint. The work was painted and usually delivered to the customer before it would start showing everything, sand scratches, pinholes and everything else that they tried to cover with primer. In many cases the proper use of primer and reducer would have prevented it. Other cases, using a product like Metal Glaze first would have done it.

Aaron
 
abuse of 2k primer is what has given it a really bad rep. like aaron says...2k primer isn't body filler or poly primer. you need to lay it wet so it doesn't bridge but you cant pile it on like poly primer. everyones 2k primer shrinks. you have to give it time!!!!

its funny...one of the big shops here...the paint helpers, which are the ones priming and prepping, most of them have never worked in a bodyshop before....and still to this day dont know the right way to do things. they pile the primer on, da it with 500 and send it in the booth....when it shrinks and you start to see sandscratches after paint, the bodyman gets blamed???? its quite funny sometimes.

always been a firm believer that the bodyman primes and sands his own work.....insurance companies have really screwed that procedure up. i'd go insane if i had a collision shop...dont know if i could sleep at night.

i do 3 coats of 2k primer....2 sessions after 1 session of poly primer.....after final prep theres only about 1 coat of poly, and 2-3 coats of 2k primer. every session including the poly gets a few days outside. Even with lower end primers like utech, done this way i've seen no adverse effects. One of my best jobs has utech p80 primer on it.....looks like it did the day it left the shop 3 years ago. this was before i found spi.
 
I've got some minor hail damage on my roof... not very deep. I was going to:
take it down to bare metal,
use epoxy on it,
evercoat filler
sand the filler
3 coats high build
3 days out in the texas sun
block it down with 400
another coat of epoxy an hour before I paint

Does that sound like a good plan for a newbie? I was thinking about glaze coating the area around the filler with a poly glaze. is that a wasted step?
 
I was told not to use anything rougher than 400 or scratches might show through the base
 
that is what a sealer coat of epoxy is for. sanding high build primer with 400 is a waste of time. you have to cut it with 180 to get it flat. then maybe run over it with 320 before sealer.
 
ok, I can cut it down with something rougher and then smooth it. thanks for the tip.
 
Might have saved me some time. I know how to cut until smooth. I wouldn't have left the waves
 
are you saying it's impossible to know when high build is smooth by cutting? I guess if you give it a lick and prayer perhaps. I may not have painted with 2K paint before, but I do know how to cut
 
lots of guys forget urethane wave starts all the way back at your primer/poly. you have to cut that stuff flat with coarse grits. think of it as the same way as you would get the wave out of the clear. You can cut the clear flat all you want...but if its in the primer you'll never get it out. proper grits and proper cure time. i dont touch poly with no higher than 80 grit....and 2k primer no higher than 180. last coat of primer/epoxy is a super smooth coat over the previous 180 grit primer and gets wetsanded smooth.
 
So you can really use 400 on clear? I would have thought it would break through to the base too easily
 
58..... They are trying to save you a lot of trouble. You cannot "shape" or "Cut" with 400 grit. It just won't happen as the surface will only be smoothed and then it will move out of the way with each pass. You need something that will "cut" the surface as you go over it. I personally use nothing finer than 180 until I am ready for primer to smooth out the sanding marks. Everything is the shape I want or is as flat as I want, and is then being sanded to remove the sanding marks. That is the only time I use anything finer than 180.

Aaron
 
no, no offence. I'll have to take you word for it. in my experience, especially when dry sanding, you can see when ridges and waves are gone by seeing when the dark or shiny spots vanish. I guess I need to add a guide coat to my list of things to do (actually I planned on doing that too, but I forgot to type it out)

I guess I'm also failing to see how waves can stay when blocking with a hard block. I can see it if doing it by hand or with a soft pad.
 
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