Prime or fill first?
Thanks,
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.
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.
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?
I was sure hoping there was a better answer that that!!!!!!!
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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
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.
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.
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
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.
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.








