sealing overtop of polyester primer
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2 days ago I had to block out a Chevelle hood that was sprayed with Slick Sand at least a year ago. It was hard as concrete! Harder than any old filler or anything else I have ever had to sand before. I also get zero shrinkage, and there are times I really pound it on. In fact I believe I could spray out 36 grit scratches and never have to worry about them ever showing back through. It is an amazing locker. And like $70 for a gallon is hard to beat. But on the last prime, it would be nice to spray something (for me) that went on a little nicer. Been spraying it with some no name gun with a 2.3 tip and almost no thinner.
I have a puck of it from the cup in my toolbox as well, probably more like 2″ thick, no cracks or anything. I have one with the Superbuild too that is pretty much the same, but it seemed to me to be a little harder to sand initially.
Have you seen any of these cars after 3+ years of them being done like that?
Jay is right though, almost makes no sense to use it on the 2nd round. If there are any bad spots that still need some work after my first round of poly, I will usually just spot those areas with more poly and block those areas out. Finish the poly out with 180 real good and move on to urethane primer. If you HAVE to do it a 2nd time overall because there are a lot of re worked areas, it shouldn’t have been poly primed int he first place. Not saying that is the case here…but I see that a lot. Just because it is restoration does not mean that you do not have to be efficient with your time.
Also would not necessarily follow the sheet on slick sand about topcoats, at that point you need to be referring to the tech sheet of whatever topcoat/basecoat you are using.
I have only been there for 1 year, but I have seen ones that were done long before I started and they look great still. But its so hard to tell on this type of resto because they are garage queens. All 100k cars and up for sure. We had a 57 Chevy come in that they said they did a long time ago (someone ran into him) and it looked like it was restored yesterday.
I also agree that poly is often used as a crutch. And maybe in the past they had a lot that had to be redone or something, so they simply go right to round 2 with it again. I know the first full resto I did there, which was a 65 GTO convertible, I did slick sand then 2k turned out great too, and surely took less time. But they simply wont hear of doing it that way anymore?
I will take a look at the tech sheet for PPG but im sure there is noting that says you cant spray on poly. The rep is there all the time, so it has to be known that it is being done that way.
I will say that my arms are pretty much jacked all the time from the amount of sanding I do on these cars!A rep doesn’t always have the right answers either, a phone call to the lab is always good to double check and verify. It may not necessarily incorrect to do it, but that doesn’t mean it is the best thing to do on a $100k show car. Being a trailer queen, doesn’t mean you get to cut corners because it may not see the elements of nature that a regular job may……but that’s just the way I look at it. These guys are paying a lot of money so why shouldn’t it be done to out live a regular job if you [i]were[/i] to expose it to the elements.
I know the reason they want to use slicksand, it is cheaper product. If you actually weighed the 2 and figure in your time you would see the difference.
me and everyone i know uses poly on their restos. very little if any shrinkage. only first round though. i will put 2k over it almost always but there have been times on smaller parts where i might finish it out to 400-600g, spray a coat of epoxy sealer on it and base. eliminating the whole 2k step. no issues there as well. everything comes out equally well in the end. as for using poly on the second round wow thats a lot of work. if it needs primer again i end with 180-220 on the poly then a quick couple coats of urethane 2k, sand and its ready to go. i believe the poly i use says you can base right on it but i have never done it. i always shoot a thin coat of sealer anyway.
Yeah i obviously have no way to tell if it will last or not. But for all I know it may outlast a regular job. No real way to tell. I would say that slick sand is surely more durable than any 2k primers. Just seems to me it would be pourous. But there has been nothing I have seen to prove that. For sure takes more time though. And we never shoot any sealer over it. Just paint right over.
And I seriously doubt they use it because of cost. In the long run a couple hundred more in materials would be nothing. These are all full frame off nut and bolt restos. No expense spared.
No expense spared but you are spraying basecoat right over poly primer. Think about that for a minute…… :stoned
I know that Standox Standoblue,standohyd, and baslick all say that a 2k sealer or primer must be sprayed inbeetween poly. Polyester spray filler is not a recomended substrate for basecoat. For this reason your waranty would be void, PPG might be diferent, but I doubt it. Upon failure you would have to rely on evercoat for waranty.
If anyone could find some literature stating it shouldnt be done you would be doing me a huge favor. Then I would have a leg to stand on for my argument.
Although on the tech sheet, it doesnt list poly as a surface it can be sprayed on, I cant find anything that says you CANT use it. I doubt that sheet will be enough to change their minds.
How about YOU just call your ppg 1-800 tech line,I have never heard of any paint company saying its ok.your warranty will also be void since you have stepped out of the PPG system.Think about it,its no different than baseing right over wetsanded bondo,you wouldn’t do that right :stoned
I will do that, and im not going to beat this to death, but bondo doesnt say it can be painted on but slick sand does. So it must not be the same as.
Hmmm 2 polyester products hardened by a peroxide hardener,sounds similar too me.Point is do what you want your going to anyway 😉
Slicksand and Standox poly are two different animals. Slicksand is waterproof and can be topcoated directly over, according to the data sheet, while Standox’s data sheet says you can do neither. Standox is also at least 3 times the price. I personally sprayed two. Wood doors on my boat with Slicksand and painted directly on top of it with Diamont D403. I’ll monitor it and report since I just did it about two months ago.
I understand that evercoat (slick sand) says that it can be directly topcoated over, but however me being in a Standox waranty aproved shop, My waranty would be void in doing this, since it is not a recomended substrate. I am surprised that this is a common practice and you guys are having good success with it. I use Slick sand and Feather fill on all my restos but always spray a 2k primer over it for finish sanding.
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