Prime or fill first?
 

Ah- so this is my first attempt at a little bodywork. I got a little rusty spot sanded down to bare metal. I assume that I fill the hole, smooth down the Bondo, then prime, then sand again? This isn't a show truck; just looking to fix a hole (or two).


Thanks,
Brian

Prime or fill first?
 

Hi Brian -

Since you're doing the repair on bare metal, you need to treat the metal because the fillers hold moisture and the rust will come back.

What I did -
1st treated with Ospho,
2nd put on a coat of etching primer,
3rd put on a coat of epoxy primer,
4th did the filler,
5th another coat of epoxy
and
now I'm blocking it out be misting with a puff can enamel of a different color to find what minor imperfections I couldn't see before.

Once I'm done blocking, I'll put another coat of epoxy then the BC/BS to finish.

I tried using the high build primer, but I didn't like it.

Prime or fill first?
 

Thanks. A little more complicated than I thought, but certainly not impossible.

Prime or fill first?
 

Hey Brian -

It's not really that complicated, just alot of steps to keep the rust from coming back.

Heck, if I can do it, anyone can.

Prime or fill first?
 

Have you ever experience your sandpaper getting clogged when sanding primer or body filler? I get it when I first start sanding but once I get through the "skin" and clean the paper, it sand like it should. I have tried many forms of sandpaper but they've all done it. Any suggestions?

Prime or fill first?
 

I've had the same problem, but then I had a bodywork friend of mine come over to show me how to block out the truck and he used real fast strokes. I noticed that he had no clogging whatsoever. I haven't had a chance to try this myself to see if that's the reason it worked for him because Steve & I are on the tail end of another project before I get back to the truck.

If I still get the clogging after trying the fast strokes I'll call John to see what I'm doing wrong and let you know.

Prime or fill first?
 

Funny thing, my bodywork friend stopped by today so I asked him. He said there's not a thing you can do about the clogging no matter what kind of sandpaper you use. He keeps a folded coat hanger handy to wack the block with when it clogs. Says it's the quickest thing he found for a quick clean. (He must have been showing me on a section I'd already started before.)

I was sure hoping there was a better answer that that!!!!!!!

Prime or fill first?
 

Hey Carlene, what is Ospho? Is this something you would recommend, a specific brand maybe? I'm getting ready to do a bunch of body stuff once it warms up. What's your preferred filler? Thanks, Blair

Prime or fill first?
 

I never thought of smacking it with wire. I have been using my hand and it gets alot off but not the little spots. Thanks for asking though, I'll give it a try next time.

Prime or fill first?
 

Hi Blair - sorry I missed this one last night (and today) otherwise I would have responded sooner.

Ospho is a rust converter. You can find it at Home Depot in the paint department. I learned this the hard way. The first time I bought it, it was from the auto paint store at about $10 a pint. I was a little ticked when I found it at HD for way less than they had it for and it I could get it by the gallon at home depot. Ospho is the name brand. Once you use this stuff, you'll have some areas that had more hidden or surface rust than you thought or where ever it ran (its an almost watery liquid). You'll notice that it's real black and raised. What I do is sand the raised area down real well and re-Ospho it. I had to do our truck a couple times this way in some spots. If you don't sand it down, it "will" show when you primer it and you'll be sanding it anyway.

My favorite filler - Rage Premium Body Filler by Evercoat and for the finish spots a product called Icing. I don't know who makes it cause the tube is out in the shop and I'm not, but it's in a verrry large tooth paste looking tube and it goes on alot thinner than the normal fillers.

Hope this helps and let us know your progress.

Prime or fill first?
 

Thanks a bunch, what you wrote was just what I had hoped, a decent product with some experienced usage to back it up, now just for some spring like days...................Thanks again, Blair

Prime or fill first?
 

Okay I'm a little new here, dont want to step on anybody's toes but....

Bondo isnt made for filling holes of any kind. Over Primer/surfacer or bare metal, it will still rust, no primer is a barrier against moisture. Depending on the maker of the primer you use (I prefer Akzo Nobel ~ Sikken or DuPont or KeyStone (cheap but works good) you might NOT be able to bondo over it. Check with the manufacturer.

Next thing, How are you getting sprayable primer? Unless you have a friend on the inside, its illegal for the genral public to purchase paint and or primer products. Not for the fact that you dont know what you are doing but more to the fact that you dont have the proper equipment to handle the chemicals(i.e. a Paint booth) Although alot of people do spray in their yards, and barns. BUT the EPA does frown on this and is a ratherlarge fine. Hope you live in the sticks or REALLY like your neighbors.


That said.. If you want to fill the rust hole, and NOThave it fall out on you in a few years... try Fiberglass, you can get the kit. w/ instructions at your local autoparts store, like AutoZone or Advance Autoparts and Batteries. You can do it over bare metal OR there is a product out called P.O.R. 15. Eastwood sells it, I have used it in the restorations and rust repair that i have done for other customers and have had verey good results w/ it. This is the stuff that they use to seal barges and such so you know that it has to be good. Once you lay the fiberglass on you can bondo over the top of that.

Another note and there is much myth on this one but you can ask the mfg'er of your favorite bondo, it does NOT hold moisture once sealed. So if you primer over it and paint w/ in a reasonable amount of time, or even seal (you can by clear in a spray can) then it will last a good while, the problem with filling rust holes with it is that water is getting in from behind, where there is nothing to protect it from the elements. Fiberglass isnt this way thankfully!

Okay Just my thoughts!
If you have Questions email me: ForeStar@Quixnet.net

Afterall we do this for a living.

Prime or fill first?
 

4star:

The way I understand it is...

1. Paint system matching Epoxy Primer on bare metal (say PPG's DP-401/40)

2. Bondo/ filler/ glass

3. Several build up coats of Sufacer Primer.

And from there moving on to the...

4. Sealer/adhesion prime (PPG DEL-SEAL).

5. Wax/grease remover (DX-330, in keeping with the system here)

and then one is ready for the paint stage.

NOTE: I left all the conditioners, sanding, evaporating/ flash times, and tack stages out for read-O-bility.

If there's a pause between sealer and paint stages, and the area is exposed to moisture, (even just humidity in the booth) you can cook it out with bake lights before progressing, no?

Funny, every time I think I know something well a new wrinkle appears. stylesider

Prime or fill first?
 

Okay, you can bondo over PPG primer, didnt know, Like i said some you can, some you can't. We are currently using Nason Selecprime and a Primer/Surfacer from PG products (keystone) neither of these recomend putting bondo over them.

My Point being, you do Not have to put primer down first, Bondo will adhere to bare metal as well as primer, I would rather have it on bare metal than primer, just in case, soemthing weird would happen to the epoxy or etching primer.

Prime or fill first?
 

Style sider and other pro painters,
The previous post refers to the steps involved in painting and as a layperson, I would like to see the entire process of painting layed out step by step to include the flash times and such.
I have always thought painting was a rather simple procedure. Strip, bodywork, prime, paint, buff, clearcoat, buff again. But most of us have never been involved in such a project.
Please take the time and define the individual steps and Carlene will see about anchoring it at the top for all of use amateurs.