The Stovebolt Site Forums The Shop Area Paint and Body Shop primer question and undercoating question

Hey all, I looked around before posting and didnt see an answer...
I have totally stripped my 56 to bare shining metal. I plan to do another sanding to get a more smooth metal appearance. what is everones feeling on at that point, after applying body work, shooting the body with some type of primer? The body guy across the street from me said dont bother, but that was a heck of alot of sanding to see it start getting spot rust. I do not plan on painting immediately, the truck is garaged, but I probably wont be able to resist driving before paint. So primer or not???
AND, I am seriously thinking of using some type of undercoating paint on the insides of my fenders. When I sanded the whole truck to shiny metal, I did the insides of the fenders too. So I was thinking I would paint the insides of the fenders with a black undercoating type paint. Anyone have an opinion on this? I am thinking less paint chips in the paint. I am also seriously thinking about using bed liner paint on the floor and steps in the cab.

I am NOT a body man or painter but yesterday I was at the guys house who is doing major surgery on my panel. With most of the metal work done (the body is stripped/blasted) he sprayed a coat of white expoxy primer on it. I've seen primers before but this light color "lite up" every pimple on the body. My understanding is expoxy is the way to go for primer and for keeping the metal safe and in good shape.
Most body men have their own "technique" so lets see what the pro's come in and say!

Under the fenders some folks use the Por15, some use the 3m spray cans and I'm sure there are others that may hold up. For me I plan to use the quart of por15 I have on the shelf...but the spray undercoating may help with noise control if you don't insulate other area's.

Do bodywork before priming. But if you don't want to do that... here is what I've used a few times before.... Use a wash primer such as PPG DX1791, followed by K38 high build primer. I've never used epoxy on anything that will be getting filler work... it just makes the primer layers too thick (mils) It is also hard to sand. If I were building a "rat rod" and not worry much about body work or paint then, yes, epoxy would be most durable.

If you decide on the epoxy, you can do your body work later.
The epoxys are designed to put filler over, then go with high build primer over your body work for final blocking.

Get it primed before the surface rust. Like Jeff said, use epoxy.
Re. the undercoating. I used a bedliner called Hurcliner. It worked very well. Gives protection along with temp and vibration reduction. http://www.herculiner.com/
Good luck!

I agree with JeffL. Epoxy prime first then put your body filler over that.
Hey JeffL - You at a restoration shop in Essex,MA? I'm also in the Boston area - I think I've driven past the shop. -wbrowne

Epoxy primer, then filler. I did this after blasting my cab. As I work the body filler I inevitably sand to metal again. Just spray epoxy again. Then 2k primer, do your block sanding then you are ready for base/clear. Below is a link to a great story on how to paint a car.
How to paint a car
I'm following this as much as possible.
Michael

Hey WBrowne,
Gullwing
No I dont work there, but I live in walking distance from there.

Epoxy primer is great for sandblasted metal.

Bare metal...don't bother? I'll not bring my stuff to that guy....Epoxy primer first for sure.you just spent hours sanding the bare metal...hold what you have dont let it flash rust or get contaminants on it.I use ospho(phosphoric-acid)(you can get it at home depot)if it does flash rust,it wipes on and neutralizes the rust then I use a dark grey epoxy primer. After all the rough body work is done,I then use a light grey high build primer.When you start sanding,by using 2 different color primers,you will see the dark primer and know when to stop sanding.Try not to cut into the epoxy primer as that is your water proof membrane. remember to use flat black paint as a guide coat every time you sand...any black that remains is a low spot any bare metal is a high spot...use sanding blocks, nothing by hand if you can help it. prime,guide coat,sand,prime guide coat,scratch putty,sand.....it's a love-hate relationship

Hi JeffL- thanks for the reply - what are you working on? - wbrowne

Hey JeffL - I forgot to ask you - do know of the restoration shop that's in Tewksbury,MA? I think it's off route 93.

I wonder if others notice the color primer Detroit puts on vehicles relating to the final color. Does it not seem that on dark colors they use a light color primer, and on a light color (white etc.) they use a dark primer. You get a chip in your paint and the result is, it is very visible.

I don't know what Detroit does, but you want to apply your final coat of urethane primer/sealer that is tinted close to what the finish color will be. That will give you better coverage with your base coat of color. The final primer/sealer coat is applied AFTER all your block sanding is done, and everything is tacked and washed with Dupont 3812 enamel reducer. Now you got a nice clean surface. The urethane primer/sealer and urethane top coat is applied "wet on wet". This means you let the primer/sealer flash (no sanding) and then spray your base coat of color right over it.

Wbrowne,
Im not familiar with any of the shops in the Tewksbury area.
Iv'e got a 45 GMC Big bolt 2-1/2 ton , that I'm extremely anxious to start on.
Right now ive been hunting for parts tha I need.
Hope to get into it after Christmas.
Jeff

epoxy primer is the best way but do not put any rust treaters or phosphoric acid rust convertors on the metal first. epoxy likes clean bare metal. I blasted mine then came back and sanded with 80 grit then epoxy. I have used several epoxies and SPI by far is the best in my opinion