2K High Build - what to do with it?
- Thread starter Arrowhead
- Start date
crashtech
Combo Man & Mod
There isn't anything wrong with 2K urethane, especially when you are allowing ample dry time. I think we are splitting hairs when it comes to the differences between 2 excellent products.
Poly primer may build more and shrink less, but I would pick 2K urethane for a front end any day, since in my experience the poly primer will stone chip easier than the 2K.
Poly primer may build more and shrink less, but I would pick 2K urethane for a front end any day, since in my experience the poly primer will stone chip easier than the 2K.
crashtech
Combo Man & Mod
There isn't anything wrong with 2K urethane, especially when you are allowing ample dry time. I think we are splitting hairs when it comes to the differences between 2 excellent products.
Poly primer may build more and shrink less, but I would pick 2K urethane for a front end any day, since in my experience the poly primer will stone chip easier than the 2K.
Poly primer may build more and shrink less, but I would pick 2K urethane for a front end any day, since in my experience the poly primer will stone chip easier than the 2K.
B
Bob Hollinshead
Use it for your last few rounds of sanding, don't paint directly over polyester primer.
Chad.S
Oldtimer
I have never directly painted over poly primer, but i'm curious as a few customers have asked my why not, and I don't have a good answer for them, what is the downside to this.
IMO, i block my poly primer with 80, then 120/180 then apply reg 2k, to me it would just be to much work to get it from 80 to something smooth enough to paint over, without breaking through all over, but are there also other reasons?
IMO, i block my poly primer with 80, then 120/180 then apply reg 2k, to me it would just be to much work to get it from 80 to something smooth enough to paint over, without breaking through all over, but are there also other reasons?
B
Bob Hollinshead
Gloss die back is what I seen when I tried it, if you use a quality sealer before you paint that is really all you need. Think about it this way-notice how polyester fillers absorb solvent when you spray primer over them?-same happens but to a lesser degree when you paint directly over poly primer then they have to come back out and kill the gloss. JMO
C
C_REX
A guy I was workin with would almost poly everything cause its so cheap(car systems) and so was he lol but anyway he would finish it with 400 and paint over the poly and with being able to see a lot of the jobs that he has sprayed I can definitely agree that it doesnt have good stone chip resistance (lots of stone chips) die back I can notice on some and some are still fine.
Now on the other hand I have did one the same procedure but with a ppg chromatic sealer and the paint still looks very nice with no die back, happy to have joined this forum, very informative and helpful.
Now on the other hand I have did one the same procedure but with a ppg chromatic sealer and the paint still looks very nice with no die back, happy to have joined this forum, very informative and helpful.
J
jeffsail
I have to say i did a firefly that my Dad use to own and drive on the hiway back and forth to work everyday the hood had dents and stone chipos like crazy. i 80 gritted hood and layed the evercoat spray filler to it with a 2.2 tip filled those dents and stome chips and such blocked and finished with 500 shot it with prospray red and cleared with montana clear .
end resut is i see the car still on the road today and i painted it about 5years ago and I have to say when ever i see the car i am like damn that hood looks good!!!!!!
so I believe if finished fine enough and mixed corectly and dry enough it will hold up as good as anything!
Jeff
end resut is i see the car still on the road today and i painted it about 5years ago and I have to say when ever i see the car i am like damn that hood looks good!!!!!!
so I believe if finished fine enough and mixed corectly and dry enough it will hold up as good as anything!
Jeff
S
sik_kreations
jeffsail;4319 said:
i use poly alot.. but i always seal over it. ur asking for problems painting over it... the lowest i sand poly is 400 grit for sealer.
F
form406
i have had bad experiences painting over poly without sealing it...too porous, solvents came back to haunt me a couple months later...
J
jeffsail
most poly filler should be sprayed wet and i mean wet !
I use a 2.2 have used a 1.8 and got very poor results. The shop i worked at had problems on a car we did and the evercoat rep blamed it on the 1.8 tip said car wasn't sprayed wet enough etc.
I have used a 2.2 ever since and i never ever need any putty on it and believe me i usally only get stuff ready to about 80 grit then spray fill with poly then i block it out 80 to 400 and then i base and clear it. I don't get carried away and never have any problems down the road.
I use a 2.2 have used a 1.8 and got very poor results. The shop i worked at had problems on a car we did and the evercoat rep blamed it on the 1.8 tip said car wasn't sprayed wet enough etc.
I have used a 2.2 ever since and i never ever need any putty on it and believe me i usally only get stuff ready to about 80 grit then spray fill with poly then i block it out 80 to 400 and then i base and clear it. I don't get carried away and never have any problems down the road.
B
Bob Hollinshead
form406;5476 said:
Same here, the times I've sprayed base and clear on poly there was always die back later on, the poly absorbed enough solvent to kill some gloss later on.