Primer????
December 30th, 2016, 06:27 PM
#1
Primer????
Seems there are as many opinions on this as there are primers!
Here is the deal. I am a novice. A mechanic not a paint and body guy. I am looking for an OEM quality paint job.
I have a project in bare metal that I hope to prime and block sand to deliver to someone that knows what they are doing to finish paint. I resently read an article on PPG VP 2050 DTM high build primer. Seems to eliminate a lot of steps. Any thoughts on this product or the best (cheapest) way for me to deliver the project to the painter.
Here is the deal. I am a novice. A mechanic not a paint and body guy. I am looking for an OEM quality paint job.
I have a project in bare metal that I hope to prime and block sand to deliver to someone that knows what they are doing to finish paint. I resently read an article on PPG VP 2050 DTM high build primer. Seems to eliminate a lot of steps. Any thoughts on this product or the best (cheapest) way for me to deliver the project to the painter.
December 30th, 2016, 06:32 PM
#2
I use transtar products. I'm a body man by trade and they have many dtm high build primers that work great. I'm currently using an eastwood brand primer for my repaint. Trying it out. So far it works just as good as anything else. If someone will paint it they will be more worried about proper prep work.
December 30th, 2016, 07:24 PM
#3
I use transtar products. I'm a body man by trade and they have many dtm high build primers that work great. I'm currently using an eastwood brand primer for my repaint. Trying it out. So far it works just as good as anything else. If someone will paint it they will be more worried about proper prep work.
This car (body shell with all glass and trim removed) is virtually rust free except 1 small area in the rocker. I have welded in a small patch panel there.. I sanded to bare metal with 60 grit DA. I understand the importance of cleaning.
What would you want me to do before I delivered it to you for base coat /clear coat
December 30th, 2016, 08:27 PM
#4
Well if you are priming over bare metal 60 might be a bit much I think 80 would be a bit better and have enough adhesion. So just go over the panels with 80. keep in mind prime shirnks. I will touch on that later. So what you are gonna want to do (and this is if i would do it) lay the primer on do 3 to 5 good coats. let it sit for a few weeks then guide coat it and block it with 180 dry find your highs and lows areas you may have not seen before you will see in primer when you block sand it . I say 3 to 5 good coats because you will block alot of it away. Once you block that down and bust through areas and fix what you find. Do another 3 coats just 3 Then dry block again but with 240 dry lightly to level the primer then wet block with 400 grit and a flexible block and then you can soft block it wet with 600.
Most painters will be ok with painting over 600 wet sand marks But most painters will also want to seal it. So you can wet block with 400 and call it done as most sealars are fine over 400 grit.
The primer i use can be applied DTM , Is high build and can be painted on once wet sanded with out sealer but the primer can me mixed to be sprayed like a sealer with proper reduction.
As a side note guide coat will be your friend wether it be dry blocking , sanding filler , or wet sanding primer.
In the filler it can be used to find high and low spots , and to chase scratches away so say you are going to finish in 180 you guide coat your filler after you used 80 grit and the guide coat will tell you when the 80 sratches are gone. It will also show if there is any pin holes in the filler.
For dry blocking primer same as filler but when you wet sand it hit it again with the guide coat to make sure your 180 grit marks are gone . You could dry 320 after 180 to cut the wetsanding down but you are more likely to bust through the primer that way. At home i still do it this way. Takes a little longer but i hate having to re prime stuff.
let your final primer coats sit a while it will shrink and the longer it sits the better . My car originally sat in primer for 3 months.
Hope this helps. It might be a bit over kill for an oem finish but its well worth it and only a bit more effort .
Most painters will be ok with painting over 600 wet sand marks But most painters will also want to seal it. So you can wet block with 400 and call it done as most sealars are fine over 400 grit.
The primer i use can be applied DTM , Is high build and can be painted on once wet sanded with out sealer but the primer can me mixed to be sprayed like a sealer with proper reduction.
As a side note guide coat will be your friend wether it be dry blocking , sanding filler , or wet sanding primer.
In the filler it can be used to find high and low spots , and to chase scratches away so say you are going to finish in 180 you guide coat your filler after you used 80 grit and the guide coat will tell you when the 80 sratches are gone. It will also show if there is any pin holes in the filler.
For dry blocking primer same as filler but when you wet sand it hit it again with the guide coat to make sure your 180 grit marks are gone . You could dry 320 after 180 to cut the wetsanding down but you are more likely to bust through the primer that way. At home i still do it this way. Takes a little longer but i hate having to re prime stuff.
let your final primer coats sit a while it will shrink and the longer it sits the better . My car originally sat in primer for 3 months.
Hope this helps. It might be a bit over kill for an oem finish but its well worth it and only a bit more effort .
Last edited by coppercutlass; December 30th, 2016 at 10:05 PM.
December 31st, 2016, 06:30 AM
#5
Well if you are priming over bare metal 60 might be a bit much I think 80 would be a bit better and have enough adhesion. So just go over the panels with 80. keep in mind prime shirnks. I will touch on that later. So what you are gonna want to do (and this is if i would do it) lay the primer on do 3 to 5 good coats. let it sit for a few weeks then guide coat it and block it with 180 dry find your highs and lows areas you may have not seen before you will see in primer when you block sand it . I say 3 to 5 good coats because you will block alot of it away. Once you block that down and bust through areas and fix what you find. Do another 3 coats just 3 Then dry block again but with 240 dry lightly to level the primer then wet block with 400 grit and a flexible block and then you can soft block it wet with 600.
Most painters will be ok with painting over 600 wet sand marks But most painters will also want to seal it. So you can wet block with 400 and call it done as most sealars are fine over 400 grit.
The primer i use can be applied DTM , Is high build and can be painted on once wet sanded with out sealer but the primer can me mixed to be sprayed like a sealer with proper reduction.
As a side note guide coat will be your friend wether it be dry blocking , sanding filler , or wet sanding primer.
In the filler it can be used to find high and low spots , and to chase scratches away so say you are going to finish in 180 you guide coat your filler after you used 80 grit and the guide coat will tell you when the 80 sratches are gone. It will also show if there is any pin holes in the filler.
For dry blocking primer same as filler but when you wet sand it hit it again with the guide coat to make sure your 180 grit marks are gone . You could dry 320 after 180 to cut the wetsanding down but you are more likely to bust through the primer that way. At home i still do it this way. Takes a little longer but i hate having to re prime stuff.
let your final primer coats sit a while it will shrink and the longer it sits the better . My car originally sat in primer for 3 months.
Hope this helps. It might be a bit over kill for an oem finish but its well worth it and only a bit more effort .
Most painters will be ok with painting over 600 wet sand marks But most painters will also want to seal it. So you can wet block with 400 and call it done as most sealars are fine over 400 grit.
The primer i use can be applied DTM , Is high build and can be painted on once wet sanded with out sealer but the primer can me mixed to be sprayed like a sealer with proper reduction.
As a side note guide coat will be your friend wether it be dry blocking , sanding filler , or wet sanding primer.
In the filler it can be used to find high and low spots , and to chase scratches away so say you are going to finish in 180 you guide coat your filler after you used 80 grit and the guide coat will tell you when the 80 sratches are gone. It will also show if there is any pin holes in the filler.
For dry blocking primer same as filler but when you wet sand it hit it again with the guide coat to make sure your 180 grit marks are gone . You could dry 320 after 180 to cut the wetsanding down but you are more likely to bust through the primer that way. At home i still do it this way. Takes a little longer but i hate having to re prime stuff.
let your final primer coats sit a while it will shrink and the longer it sits the better . My car originally sat in primer for 3 months.
Hope this helps. It might be a bit over kill for an oem finish but its well worth it and only a bit more effort .
December 31st, 2016, 07:05 AM
#8
Old(s) Fart
Join Date: Mar 2007
Location: Northern VA
Posts: 47,268
You need to know what type of top coat you will be using. You'll be money ahead if you select a primer that is compatible with the top coat. Yeah, you can use a generic primer, but they you either have the risk of incompatibility or the extra steps and cost of a seal coat.
December 31st, 2016, 08:44 AM
#10
I have never seen paint lift because incompatibility. To me that's like a wives tale. Think about it. Once the primer dries. It's cured. The only way it will re activate is if you use diffrent chemical based coats. Like acrylic vs enamel etc etc. Usually it's bad prep work. Once the primer is dry you are relying on mechanical adhesion. Guys will seal over primer to use that window to top coat and get the chemical adhesion once the sealer is dry it has to be sanded for paint to stick properly. I rarely use sealers and paint right over primer. I have never had paint peel or flake on any of my personal cars or side jobs. Paint companies want you to use their products for warranty issues. But guess what If you do your own work warranties is void. Lots of variables. Most warranty issues come down to crappy work.
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