Painting a not quite antique

[Wheelmang]

Finally got to painting my wife’s car. It is sanded and all the little dents dings and scratches are filled in or feather edged out and the entire car is blocked smooth. Looks like some favorable temps starting Friday to Sunday. The plan is prime, base and clear. It is not a high build primer. The question for all the painters out there is do I need to sand the primer before laying down the base coats? I hope not. Cannot stand the masking and sanding another coat means remasking after the sand and wash.

thanks all for the help

Paul

[1937hd45]

Depends, do you care what the finished product looks like? Bob 

[Wheelmang]

Thanks Bob.

Yeah it’s a Jag and my wife’s so guess you answered it. Put a lot of hours into it so far so guess what’s a couple more weeks waiting for some more optimum temps and the time to remask?

[GARY F]

you do not have to wet sand the primer

[DavidMc]

The areas where scratches that have been feather edge sanded out, are going  to be visible on the finished paint.  So you will need to spray with a high build primer followed by a guide coat then block sand to remove the highs and lows.  You may have to repeat this process until the block sanding removes the guide coat without rubbing through to the base anywhere.     It is very time consuming.

[28 Chrysler]

Primers need to be sanded or scuffed unless it states that you have a non sand-able primer, such as a primer/sealer.

[old car fan]

Yes it  is a resand,It may take several coats and a lot of blocking.

[Frank DuVal]

Do you mean there is NO primer on it after the work you have done? 

 

4 hours ago, Wheelmang said:

little dents dings and scratches are filled in or feather edged out and the entire car is blocked smooth

 

To me this would indicate all the worked areas have been primed and then sanded "flat". I do not know how one would feather edge then block the entire car without adding primer. One would have just blocked the original paint, and to get it "flat", most of the paint would have to be removed.

 

If, however, the worked areas have been primed, then the whole car blocked "flat", then usually (not show car work) one just seals, color, clear. No sanding between these processes.

 

To your original question (to sand or not), that should be asked of the paint and material supplier! They are the only ones that know what products you have bought and the particular instructions for them. Especially today, one answer does not fit all.

[Rusty_OToole]

Back in the day the proper practice was to primer the car with 3 thin wet coats of lacquer primer surfacer, sand dry with 100 or 120, primer again 3 thin wet coats and sand with 400. Take off all masking, clean and blow down the car thoroughly getting all the dust out of every crevice  around windows, cowl vent, door jambs, trim etc then mask again.  This was for a regular enamel job, a real nice lacquer job required finer sanding and of course today's paints are more finicky.

 

Short answer if you don't want dust in your paint job you have to strip the masking off, clean the car thoroughly as you can and remask.

[nickelroadster]

My advice would be to not get in a hurry.  Keep priming  and blocking until it is ready.  Even then it would be advisable to use a primer sealer before painting as this will improve the adhesion.  There is a reason that paint jobs are so expensive.  Even when you know what you are doing it takes a lot of time and rushing can ruin the whole job.  Good luck!

[Akstraw]

I suggest that you consult the manufacturer's guidelines for the specific brand of paint that you are using.  The primer that I use does not require sanding if overcoated within a specific time window; after that sanding is recommended.

[mike6024]

http://us.ppgrefinish.com/PPG-Refinish/Products/Automotive-Refinish/Deltron

 

If you're using PPG you can look up the product data sheets online. It seems you don't need to sand for adhesion purposes, unless as mentioned above if you exceed the "time window" between coats you need to sand and wipe with the surface cleaner.

 

Here's an example of what it says:

 

Note: DPLF Epoxy Primer may be recoated any time up to 1 week. After 1 week, it must be cleaned, sanded and recleaned. Reapply 1 addional coat of DPLF Epoxy Primer only if applying basecoat directly to DPLF

 

[R Walling]

 Back in the old days, I would DA the car with 180 grit paper, tack off and spray one coat of non sanding primmer-sealer and then three coats of enamel, all in one day. ($80.00 please, thank you)

 

 You could DA a whole car with 400 grit, tack it, and spray a non sanding primmer-sealer and then top coat it. It will be a good looking 30/30 finish* that won't peel off. 

 

*(30 feet at 30 mph)

 

 In your specific case, tack it , spray the non sanding primmer-surfacer and then the top coats.

 You could spray one or two extra top coats so that you could buff out some small defects later.

 Not every paint job has to meet everybody else's standards.

 

 Buffing a new bad paint job always makes it look better because it removes the new look and the criticism from the "know it all's."

Edited March 15, 2018 by Roger Walling (see edit history)

[Wheelmang]

Thanks all for the feedback. Perfect temps today so spraying the primer. Bad day for painting tomorrow so hope to get the coats of primer sanded and car cleaned up and remasked tomorrow or Sunday and then the next good temp days will get to base coat and clear. 

Will post a few pics when all done. Not going for Concour quality just a pretty car. I did take off everything I could though. It has been 40 years since I tackled a full respray. The last one was a church bus. That took a little more paint than what I am using here but was probably a lot less work that what is put into this. 

Thanks again for all your valued input.

Paul 

[R Walling]

33 minutes ago, Wheelmang said:

Thanks all for the feedback. Perfect temps today so spraying the primer. Bad day for painting tomorrow so hope to get the coats of primer sanded and car cleaned up and remasked tomorrow or Sunday and then the next good temp days will get to base coat and clear. 

 

 After sanding primer, be sure that you give it a coat of non sanding primer/sealer 1/2 hour before the color.

 It will stop sand scratches in the top coat and will give the surface an even color coat so that the top coat will cover better with less coats.

 It also bonds the color better to the surface preventing flaking.

[Wheelmang]

So as I said it has been a very long time since I painted a vehicle. Total novice with an HVLP so OK to laugh  at what may seem some basic questions. I have extreme orange peel in the primer. I tried various pressures at the inlet with various adjustments to the air and paint out. Finally got the best coat and pattern on the 3rd coat with both air and paint wide open but was running close to 40 PSI at my inlet. From everything I have read that is a lot of pressure for an HVLP gun. (Especially when it says 30 PSI max on the gun) I found when I was cleaning up afterwards that the gun had a 1.3 tip. Would that have caused my orange peel problem? Again from what I have read the gun should be at something around 10 PSI and I think that is what the data sheet recommended?? Is that for paint and clear as well? 

 

6 hours ago, Roger Walling said:

After sanding primer, be sure that you give it a coat of non sanding primer/sealer 1/2 hour before the color.

 

I am thinking I should have saved a lot of reading and just ask the questions here. So here come a couple more.

Sanding primer with 180 then 220 (or more) with a DA or by hand blocking?

It took two quarts of primer for three coats. It's a convertible.  My base is a 1 - 1 mix so does that mean the two quarts is enough for up to six coats? Is there any advantage/disadvantage to that many coats? Maybe just save some for what ever may come down the road. 

Color sand only the final clear coat 1000 up to 2500 wet? How long after is it good to sand?

Should the clear coat be put on the same day as the base or should I wait a couple of days?

A lot of questions but I think you guys are better than the books!!

Thanks

Paul

 

[Bill Harmatuk]

You guys keep talking and I'm gonna paint my old Chrysler.

No Pebble Beach and no Amilia Island in the plan. Just correct and nice. I've even thought about painting over a few imperfections. 

(Every ding has a story.) Its an old car. Thats what I want it to look like. May be not.

 

I've primed and painted the underside and I was amazed at how good it turned out. I was quite proud.

15 PSI at the gun. 80 at the compressor. I think a 1.4 tip. Might be wrong. Smooth as silk.

 

I can paint. Have done body work. Have lights. Fans. Desiccant filter. Google and You Tube. PPG 2 part Epoxy. 2k sealer. DON'T have, confidence.

I'm getting close to needing to make a decision as to do it myself or trust and pay some one to ass my car up.

if you look at the people that paint, you can tell real quick it ain't rocket science.

 

Worst case.... I'll be doing some buffing. I'm Using single stage.

 

Bill H

 

 

[R Walling]

1 hour ago, Wheelmang said:

Color sand only the final clear coat 1000 up to 2500 wet? How long after is it good to sand?

 

 

1 hour ago, Wheelmang said:

 Is there any advantage/disadvantage to that many coats?

 

"Sanding primer with 180 then 220 (or more) with a DA or by hand blocking?"

Sand the primer with 360 or 400 grit paper.

Surface primer that you sand is only necessary to fill in coarse sandpaper scratches.  Use as necessary, not needed over 360 or 400 grit scratches. Excess primer or paint should be avoided.

 

"Color sand only the final clear coat 1000 up to 2500 wet?"

If you are not looking for a real special job,

 you can skip the color sand as long as you don't have a lot of dust in the finish.

 

"How long after is it good to sand?"

 Some paints have to be sanded a few days after shooting or it becomes real hard.

 

 Some paints can be sanded within hours of spraying.

 When in doubt, read the instructions.

[R Walling]

6 minutes ago, Bill Harmatuk said:

I've even thought about painting over a few imperfections. 

(Every ding has a story.) Its an old car. Thats what I want it to look like. May be not.

I can paint. Have done body work. Have lights. Fans. Desiccant filter. Google and You Tube. PPG 2 part Epoxy. 2k sealer. DON'T have, confidence.

I'm getting close to needing to make a decision as to do it myself or trust and pay some one to ass my car up.

Worst case.... I'll be doing some buffing. I'm Using single stage.

 

Bill H

 

 

 Go ahead and paint it!!!  It is more gratifying to learn, than to pay.

 

 (Don't skip the feathering of the chips and scratches though, they will make runs in the wet paint!)

[mike6024]

1 hour ago, Wheelmang said:

I have extreme orange peel in the primer.

 

The guys at the automotive paint retailer recommend a "splash" of reducer (ie thinner) to thin it out a little and spray easier and smoother. That was for the epoxy primer I was buying, but is probably applicable to all others.

 

 

[1937hd45]

Learn to get primer to lay flat, you sure don't want orange peel in the last sealer coat. Bob 

[RansomEli]

1.3 tip is a bit small for primer. That's for your final coat. Most paint guns also provide a 1.7 or 2.0 tip for primer. 

 

Just a guess, but it sounds like you did not thin the primer enough. Maxing out the gun and still getting a rough primer coat means you're not thinning the material enough. 

 

Don't worry, you'll get the hang of. We've all made mistakes, which is how you learn. 

 

And don't forget to keep your air supply moisture-free. 

[Wheelmang]

13 hours ago, Bill Harmatuk said:

You guys keep talking and I'm gonna paint my old Chrysler.

Just me talking Bill but go for it! Even with the mistake on the primer "I did it" not someone else working on my car. When any of my restoration projects are complete there will be the personal satisfaction (with much guidance from everyone on this site) that it was done by me (no ego here just personal satisfaction) including all errors, mistakes and corrections. How may times have you had to take a vehicle back to a dealer / repair shop because the problem is still not fixed. At least we can make the mistakes and correct them ourselves - and the labor rate is? 

 

Edited March 17, 2018 by Wheelmang
Wordsmith (see edit history)

[Wheelmang]

A couple of comments were made about some thinning on the primer. That makes sense - post error. I did read the TSB on my particular primer and there were no suggestions or recommendations to that effect so a couple lessons learned.

1) check the tip size before starting. I have a 1.8 that I should have used for the primer. 

2) In some (most) cases the experienced people on this site know more than the TSBs.

 

Also just for chuckles - the threads on the bottom of my paint can that attach to the base mount on my paint gun is left hand thread. (WHO KNEW) I guess the gray primer will wear off my hands in a couple weeks and the huge gray blotch on my shop bench and floor will be a reminder the next time I have the gun out.  Oh and in the middle of that mess I stepped on one of those sticky mouse traps. Would have made a great You Tube moment 

Edited March 17, 2018 by Wheelmang
Text add (see edit history)

[Janousek]

Sand your primer with 400 grit if it's a solid color.  Buzz over your 400 grit sanding with a 500 or 600 grit da if it's metallic.  We used to use 320 with laquer/enamel jobs but you see less sand scratches later by going finer on paper.  

 

What brand/model primer are you using?  

 

All of my hvlp are usually running 36 psi at the gun.  HVLP is like a catylitic convertor for your car.  Those recommendations are for compliance laws more than performance.  At the20psi recommendations my Iwatas suck.  

 

You'll want at least 4 coats of wet clear if you plan on starting with 1000 grit.  I don't recommend it for a newbie.  You'll just make a mess and have a bunch of sandthroughs.  A safe bet for a decent looking job would 1500 da the paint and then polish it.  It's not the best and you still have urethane wave but at least the paint will be orange peel free.  

 

SPI has one of the best forums for painting they you will ever find.  This is a great forum but a lot of the paint advice is sketchy or very outdated.  

[60FlatTop]

I think I painted four of my Wife's cars with a brush. I washed them pretty good first.

 

I remember her being as happy as the time I bought her shoes, or her Pinto.

[R Walling]

Wheelmang 

 If you haven't sanded out your orange peel primer yet, use a 8" sanding block with a slightly soapy water mixture. (360 grit)

If you go through to  bare metal, don't worry, the primer sealer will bond to the metal. Just don't remove the old primer from the deep sand scratches.

 

 Very messy but 100 times quicker. Wash the trunk and fender areas that you will not be painting along with the entire car and blow out all cracks and mouldings to eliminate the water. 

[Bill Harmatuk]

4 hours ago, Wheelmang said:

Just me talking Bill but go for it! Even with the mistake on the primer "I did it" not someone else working on my car. When any of my restoration projects are complete there will be the personal satisfaction (with much guidance from everyone on this site) that it was done by me (no ego here just personal satisfaction) including all errors, mistakes and corrections. How may times have you had to take a vehicle back to a dealer / repair shop because the problem is still not fixed. At least we can make the mistakes and correct them ourselves - and the labor rate is? 

 

And I don't have to put the body on the chassis to haul it around to everyone to get quotes that are going to break the bank.

Satisfaction is the KEY word here. Procrastination is another thing.

I will save a lot of time by doing it myself. Probably a better job too.

 

Thanks, Paul.