Update "Perfect Paint Job" with sanding grit suggestions?

J

jeff33702

Looking through the Perfect Paint Job as I'm getting close to actually painting something and realized that I've had to look other places for sanding recommendations (I'm a newb). Would be great to get the sanding steps mixed in with the painting steps!

Thanks!
Jeff
 
I also recall on the old forum a write-up on the different grits. 600 and _600 were not the same. I forget what was in the blank. This should make sense to someone hopefully
 
Whiskyb;5837 said:
I also recall on the old forum a write-up on the different grits. 600 and _600 were not the same. I forget what was in the blank. This should make sense to someone hopefully
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I recall that post and I believe it is a P600 designation for ISO graded abrasives versus the 600 CAMI designation. This link has a table that shows the relationship:
http://en.wikipedia.org/wiki/Sandpaper
 
jeff33702;5836 said:
Looking through the Perfect Paint Job as I'm getting close to actually painting something and realized that I've had to look other places for sanding recommendations (I'm a newb). Would be great to get the sanding steps mixed in with the painting steps!

Thanks!
Jeff
Click to expand...
I thought it already had some sanding recommendations (these are direct quotes):
  • Starting with bare metal, Dual Action sander with 80-grit before epoxy.
  • wet sand the epoxy with 400-800 then spray the base.
  • After two coats of base the vehicle should set overnight then do any minor wet sanding with 800-1500 grit sandpaper to remove any orange peel or trash.
  • wet sand the clear with 400-800 grit sandpaper to block out any orange peel or dirt.
  • If any wet sanding is required before buffing sand with 1500 grit sandpaper then set the vehicle in sun for two to three hours.
You are right about needing more detail if you are a newb but you probably should look or ask for more guidance in this forum. Under Shop Talk, the sub-topic "Wet Sanding/Polishing/Detailing" has quite a few posts and if you don't find what you want there, post a new thread and ask for more detailed guidance. The people on this forum are the best and most reliable source of information on paint and bodywork I've found on the whole Internet. And it's FREE!
 
Bob Heine;5840 said:
I thought it already had some sanding recommendations (these are direct quotes):
  • Starting with bare metal, Dual Action sander with 80-grit before epoxy.
  • wet sand the epoxy with 400-800 then spray the base.
  • After two coats of base the vehicle should set overnight then do any minor wet sanding with 800-1500 grit sandpaper to remove any orange peel or trash.
  • wet sand the clear with 400-800 grit sandpaper to block out any orange peel or dirt.
  • If any wet sanding is required before buffing sand with 1500 grit sandpaper then set the vehicle in sun for two to three hours.
You are right about needing more detail if you are a newb but you probably should look or ask for more guidance in this forum. Under Shop Talk, the sub-topic "Wet Sanding/Polishing/Detailing" has quite a few posts and if you don't find what you want there, post a new thread and ask for more detailed guidance. The people on this forum are the best and most reliable source of information on paint and bodywork I've found on the whole Internet. And it's FREE!
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I think you realize that you took most of that out of context.
"The epoxy should set for 2 hours before spraying basecoat or the next option is let it set over night and wet sand the epoxy with 400-800 then spray the base."

"Option if your basecoat isn’t perfect:
After two coats of base the vehicle should set overnight then do any minor wet sanding with 800-1500 grit sandpaper to remove any orange peel or trash. "

Both good information - but not sanding "steps" in relation to the perfect paint job.

I'm a fan of searching - I do a lot of it. It's because of that searching that I ended up back her to make this suggestion.

It seems to me that one of the biggest problems a new painter has is coming up with a "plan" or order/steps in which to do things. Searching is fine and dandy but if you read 10 people's how-to articles, you get 10 different methods and opinions. That's one of the reasons that I love the perfect paint job article..it's from one source. I was simply saying that it would be awesome to get it complete with sanding steps too - because from ONE source, it would give the beginner a better "template" to start with, tweaking little things as needed.

That is all.
 
By the "ONE" source, you are referring to none other than Barry Kives folks..
 
Jeff,

I agree compltely. I made a similar suggestion recently. It would take some work, but I would like to see the Perfect Paint Job completed with detailed, SPI endorsed how to info for each step frome bare metal to buffing. My suggestion resulted in the Tech Tips section, which is becomming a great addition to the site. However, tt would be so nice to have a guideline to follow from a single source. For example, I posted about buffing a while ago. I got so many different perspectives that I got more confused the more I read. I ended up calling Barry so he could help me sort everything out so I could purchase my supplies.
 
Sanding steps would be very hard to do, as everyone does it different and there is a big difference between old painters like myself and new painters.
Example, I block filler with 40 and then 80, I block primer with 180, I base over 320 dry be it the silver base on the vette, before you apply the blue or be it black.
This goes against all new procedures as far as how new painters are trained.

The vette has only been buffed once with a black presta pad and ultra cutting cream but like I told bondoking, I'm going to play with it before I do the next four buffing steps and there is no sand scratches in the paint that was applied over 320 dry.
 
Thanks for the reply, Barry. That is how you told me to do it a while back, and I have been doing exactly what you said. So far, I have had what I think are good results per time spent. Had I not talked to you, I would have been working my butt off with paper that is too fine. I would have never got the car smooth, because I would have been pushing too hard on flexible panels just trying to get something done. I am hoping to spray base/clear on my 34 this spring, so I'll probably be hitting you up for more advice on that as I need it.
 
my go to paper is 100 grit . it is the last paper on filler and the first on epoxy . i block my first coat with 100 then move up 180 .
 
Shine,

I can see where the 100 grit would be just right.

I often find myself using 80 on my first time over primer on flexible panels. On the hood I am working on right now, anything more than the weight of the sanding block distorts it, so I have to use new, 80 grit to get anything done. It is a 34 Chevy hood, so it is just one curved piece of metal. I always try to get the 80 grit scratches out with 180 before I recoat with primer.

I know it has been disputed on here before, will Turbo shrink in 80 grit scratches? I try to take them out just to be safe.
 
when working on the early tin i work on a bench and use foam and old tshirts to support the panel . this stops the flex .
 
Some people do use turbo over 80 grit scratches but I know if I ever did they would haunt me after the paint goes on so I don't chance it.
 
to me 2k over 80 is asking for shrinking.. doesnt take much to just go over with 150.
 
a lot of guys do it, but i'm in the same boat..just too risky for ME. think you can get away with it more in the south with the summer heat and sunshine.
 
jeremyb;6077 said:
a lot of guys do it, but i'm in the same boat..just too risky for ME. think you can get away with it more in the south with the summer heat and sunshine.
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maybe not after its painted.. give it some time.. most of the time it will shrink.
 
I'll continue taking out the 80 scratches with 180. I bet the stars have to be aligned just right to see any shrinkage with a quality product like Turbo, but for all the longer it takes, there is no need to risk it.
 
quality or not.. its asking alot of a urethane product to holdout over 80grit to primer to paint.. keep in mind most of 2k primers are used in crash shops.. what shop in there right mind would primer over 80 and have 80 grit scratches into oem paint.. thats just asking for problems.. the bare minimum to most is 150.. i prefer 180 da and have no problems hitting and feathering with 320 and hitting mud with that for a crash style repair.
 
Thanks for the answers guys, this is exactly why I cannot put suggested sanding grit in the perfect paint job.
Bottom line, is everyone does it different and it does not matter how you do it as as long as the results are what you want.

A good example, is weekly, I will get a call where a jobber sold a production shop one of our clears, the painter reads the perfect paint job and calls me in a panic,
I do not have time to let the base set overnight before clearing.
 
Yeah, I can bet that overnight wait for clear gets a lot of people confused when their paint tech sheet says 20-30minutes. The proceedure may save a person from having delamination problems if he applied the base heavy and fast with a fast reducer(worst case scenerio), it'll also help to remove any chance of solvent pop and gloss die back. Sometimes collision shops don't even realize they're having dieback problems because the work goes out the door so fast-then 6 months later they happen to see one of their jobs and it has lost 20% of the shine. The problem with writing tech sheets is there are always a lot of variables. The guy who finishes his filler in 80 grit, hammers on three wet coats of primer with slow reducer, lets it flash well and puts it in the sun at 180* for an hour will probably have better results than a person that shoots at 60* with metal temps of 50* using fast reducer and no bake. Lots of variables, so you're best off recomending a grit, proceedures, temps, etc... that will work for all. I see the same situation when reviewing I-Car repair proceedures and OEM car manufacturerer repair proceedures- the Engineer in charge of writing up the repair proceedure has no idea what the welding skills are of the technician so they develop a proceedure that works at an average skill level or they say no repair options at all-liability reasons.
 
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