we are using a light grey PPG Multiprime fast drying primer. we sprayed it about 3 days ago and there is a rough texture evenly over then entire car, including the fiber glass hood. the primer also has a shine to it. we sprayed the car at about 65 degrees but it gets to about 20 degrees at night. any suggestions of what could cause this or if its normal...im thinking it can be lightly sanded smooth but im afraid of the base coat doing the same thing. thanks guys
primer/painting problems?...please help
- Thread starter 19mustang65
- Start date
19mustang65 said:
Didi it do it imediately ? Or when it dried ? Sounds like fish eyeing. If I remember right, if it did it right away, it is from too much air pressure or gun is too close. I wouldn't worry too much. You need to sand the primer anyway and also sand the base and clear. My buddy did autobody for a living and told me one time you need a special additive for the fiberglass hood or any plastic or flexible parts to keep the paint from cracking when the body panel bends and flexes. Do you have any pics ?
primer is going to be some what rough after it dries, as it is basically paint that does not have a sealer built in, and is loaded with solid material so you can build up the primer to fill minor sanding scratches and other small imperfections. you need to sand the primer smooth before you lay down a second coat. then lay down a guide coat, a color that is far different from the primer color so you can see when it is removed, so you can tell where the high and low spots in the metal are. once the guide coat can be sanded off uniformly, you can lay down the color coats followed by the clear coats of paint.you will need to sand the clear to remove the orange peel that always forms as the paint dries.
the rough texture was there when we sprayed also. my base coat is metallic so i dont want to sand it...the car was sanded down to bare metal. so i dont think the fish eyeing(bleeding through from the underneith paint) would be the problem. the primer hasnt completly dried yet either. but then again it gets really cold without the heater going at night and when we arnt hhome.
primers will go on rough. You can doa websearch and find some good examples of fisheyes.
From what you have said, I would say it is ok. Get some 400-600grit and wet sand it smooth.
Do you have a reference book? You should get one if you don't. Make sure you sand diagonally. And use a long board.
From what you have said, I would say it is ok. Get some 400-600grit and wet sand it smooth.
Do you have a reference book? You should get one if you don't. Make sure you sand diagonally. And use a long board.
khiggins
Founding Member
Hi there, the problem that you are experiencing is probably due to a lack of paint flow at the gun and/or too much air. This rough texture is usual know as "dry spraying". Try thinning the primer a little more and adjust your gun for more paint to flow from the tip. Also, make sure you have the correct pressure for the primer at the gun (account for the length of air hose you are using.) Hope this helps. 
19mustang65 said:
I found a Hot Rod Paint & Body magazine that had good info and pictures. Also Shilton or Haynes manuals work pretty good. I have also purchased a How to Paint your Mustang from Cal Mustang recently.
Try your library, local bookstore or Amazon.com for some others. Talk to the guys at your paint shop too, they are a very good resource.
Also do some practice sprays against cardboard or newspaper so that you get the flows set correctly. And get gun regulator so you can adjust the pressure at the gun. Use an in-line filter (the orange diposable kind work good).
paint
Here is your mistake
the body was degreesed prior to primer
What did you use to degreesed the body of the car???????, One time I used a rag with a light coat of thinner to take any dust as well as oil on the body right before shooting the primer and got the same thing...... It all comes down to prep work....
just sand down like everyone suggest and learn from your mistakes
good luck
Here is your mistake
the body was degreesed prior to primer
What did you use to degreesed the body of the car???????, One time I used a rag with a light coat of thinner to take any dust as well as oil on the body right before shooting the primer and got the same thing...... It all comes down to prep work....
just sand down like everyone suggest and learn from your mistakes
good luck
68rustang
Active Member
You would get much better answers if you could somehow post a pic of what you are talking about. I think I know what you are describing. I have seen the same thing on my car which is in primer now, and a few bikes that I have painted. It has never been a problem. However if it is a "dry" spray then it is best to sand and repaint.
Better than buying a book would be to make friends with a bodyman Or pick the brains of the guys behind the paint counter. Tell them what you are doing and where you are doing it and what equipment you will be using. If they won't talk buy your paint somewhere else.
Better than buying a book would be to make friends with a bodyman
Or pick the brains of the guys behind the paint counter. Tell them what you are doing and where you are doing it and what equipment you will be using. If they won't talk buy your paint somewhere else.well we sanded the primer...she looks good now.. its a dull finish instead of a shiny bumpy finish. the primer originally said to not thin(cali laws i guess) but the paint store told me to thin in 25% so we did that. i have a presure guage on the gun it self so we are good there. we will spray on the base coat in the next day or so hopfully. any suggestions on that?
also, when we do the clear coat, which ive never sprayed before...anybody know how to do this well?
thanks again guys
also, when we do the clear coat, which ive never sprayed before...anybody know how to do this well?
thanks again guys
68rustang
Active Member
19mustang65 said:
shoot the clear on a practice piece before you hit the car with it. I don't know about warmer climates where you are but in Ohio in the winter I have to thin the clear with reducer a bit. Otherwise it comes out of the gun like syrup.
zookeeper
Founding Member
I think you're overlooking THE cardinal rule of painting, which is to follow the manufacturer's tech sheets. Wherever you bought your materials, they have Product Information Sheets, or "P-sheets" as they're called. These are usually handed to the customer with the primer, paint or clear at the time of purchase and are full of answers to the questions you have. Variables like, reducing ratios, spraying temps, tip size for your gun and surface prep are all covered as are such important items like safe use of the product. But here's what I do for primer: first make sure the surface is clean. I do this with a final wipe degreaser. I use House of Kolor's stuff, but any good brand will do. Don't allow it to dry on the surface, just wipe on, then wipe off with a dry, clean rag. Next, I mix the primer and strain it into the gun. Since I use an epoxy primer, it's not necessary to thin it, jusy mix part A to part B and strain it into the gun. If you're using something like a lacquer primer, you need to thin it 100%-125%. If your primer isn't going on "wet" enough, check your tip size. I use a 1.8 tip, but most primers will be better off with a 1.5 tip. You should also have a guage/regulator on your gun. If not, they're only about $20, buy one so you KNOW what the pressure is at the gun. Most HVLP guns need about 20-25 lbs at the gun to work properly. Also, make sure if you are using an HVLP gun to keep your gun close to the surface (about 5"-7") and parallel to the surface. I highly recommend picking up a copy of House of Kolor's books by Jon Kosmoski, they're on ebay all the time and are excellent books to help someone get pointed in the right direction, regardless of paint brand. Hope this helps.
68rustang
Active Member
19mustang65 said:
I was spraying at about 68*F. What zookeeper says is correct. I would talk to the guys at the store and see what they recommend. For the PPG stuff I just sprayed we were able to reduce the clear something like 3 parts clear to 1/2 part reducer. This was all on the recommendation of the distributor. It took a little longer to dry but the end result was much better.
69 Rustang
Member
zookeeper said:
Ask for copies of the manufacturer's technical data sheets (TDS) or go on line to the paint manufacturer's web site and get them. It is imperative that you read these to know that your gun settings, mixing ratios, reducers used, etc are all proper for what you are trying to do. There are many variables that the TDS will cover. Some things, like gun tip size and air pressure are vital for getting the proper appearance.
Someone above said that you needed to sand the basecoat prior to clearing, this should not necessarily be the case. With most 2 and 3 stage paint systems this is not necessary. Refer to the TDS to find out what the window is for proper flash time and maximum time prior to clearing.
Good luck with your paint job.
