painting question

[Anonymous-0]

I sand down with 220 then prime, wet sand with 400, then final coat of paint. I can see sanding marks. Should I put other coat of primer on or what?

 

[Patsdeere]

I would try sanding with a finer grit. I start with a 220, then 320, then 500 and in between color coats I use 500 (it I have a run/oops) or 1000.

 

[glennster]

are the scratches from the wet sanding or from the body work portion. are they heavy from the 36-80 grit when the metal and body filler was done, or from final sanding?

 

[Anonymous-0]

Well I never noticed it when done priming. So I assuming its from the wet sanding.

 

[CNKS]

What kind of "primer"? Best thing to do is to use epoxy primer, then cover that with a surfacer or primer surfacer. Those will fill 80 grit sand scratches. If you just used a cheap "sandable" primer, that is the problem.

 

[PhilC]

What kind of "primer"? Best thing to do is to use epoxy primer, then cover that with a surfacer or primer surfacer. Those will fill 80 grit sand scratches.

Man, if I shipped a repaired panel to the paint shop with 80 grit scratch marks the painter would come looking for my a**! :shock: No bodywork goes across to paint unless it's been finished with a minimum of 150, but I finish everything with 180 before it gets primed. :wink:

Fred - What are you wet sanding with 400? Primer or color? We use 400 to prep surfacer and color for sealer. If the sealer needs nibbed, it gets done with 600 wet or 800 dry on a DA with a foam interface pad.

If you're wet sanding color with 400, it's too coarse and that's why you're seeing sand scratches.

Just my $.02. :wink:

 

[glennster]

if they arent showing when primer is applied, could be the primer is bridging over the heavier sanding marks from the metal work. then when your colorcoat is applied, the reducer in the color coat causes the primer to sag into the sanding scratches. we use a product call "icing" at the shop for the final skim coat before priming. its pretty much a liquid body filler. mix it like bodyfiller and apply , then sand smooth. use 180 or 200 to finish the icing down, then prime and block sand. if you suspect the sanding scratches are coming from sanding the primer, try applying a guide coat of primer after you sand the first coat of your fill primer. its nothing more than a thin coat of primer a different color. block sand the guide coat and watch for scratches in the first coat of primer. you can buy a spray can of guide coat from any body shop supply. once you figure out where the scratches are coming from, then you can solve the problem. good luck with it!!!

 

[CNKS]

I usually start with 80 grit, but I have removed paint with a fiber wheel on an electric drill, that is a lot worse than 80, or 36 for that matter. I do spend a lot of time sanding it with 150-180 before priming, I do not know how much I am getting rid of the damage though. About 3 applications of 3 coats each of Omni MP182, sanded in between of course, covers it. That has been my experience. I have also had zero problems sanding with 400. Remember I don't run a body shop, and probably do a better job of preparation than they do. Time is not money to me. DA sanders are nice, but not essential, I do have one. Since I have a lot of time, I feel I have more control hand sanding. I will stand my my 80 grit statement, those are not that deep.

 

[Pat-CT]

i spend alot of time on primer and this is my first tractor painting etced then filler then sealer if you do that i dont see how scratches should show threw that

 

[Dick L]

I am not a body man or a painter but I did stay at a Holiday Inn. My guess is after the 220 you didn't spend enough time sanding with the water hose and 400 grit. If you are not using water the paint sticking to the sand paper will scratch. I paint over the 400 grit sanded primer and then use 400 grit with water on the paint before the final paint. It usually turns out well enough for a work tractor.

 

[Dick L]

I always sand until all the scratches courser than 400 grit are gone even if I have to go to bare metal and re prime. Sanding is scratching off the paint. Using 1000 grit is still scratching off paint. Just harder to see with your eye.

 

[CNKS]

Best not to use a finer grit than what is given on the spec sheet, because you might not get good adhesion of the topcoat. For example the instruction sheet for PPG Omni MTK acrylic urethane says to use 500 grit for wet sanding surfacer. I sometimes use 400, then 600 prior to topcoating, never finer than that. The topcoat will hide those scratches. Any visible scratches left by 4-600 are caused by improper sanding.

 

[Anonymous-0]

Give more info. Type of primer? Number of primer coats? Drying time? Sanding grits? Use a guide coat? Paint type? Amount of reducer in paint? Number of paint coats? Using many coats of primer to fill grinder scratches will shrink for months after painting.

 

[PhilC]

About 3 applications of 3 coats each of Omni MP182, sanded in between of course, covers it. <snip> I will stand my my 80 grit statement, those are not that deep.

And therein lies the answer, the MP 182 tech sheet calls for 2 - 4 coats over a surface prepped with 120 -180 grit and you're using double that, no wonder you can fill 80 grit scratch marks.

I'm with glennster, I'd rather glaze than spray & sand, spray & sand, spray & sand, etc. That's what glaze is for. I prefer Dolphin glaze and love it's self-leveling properties, but any polyester finish filler works well for that final touch. Block once with 180, spray [i:31f5b6aa1c]maybe[/i:31f5b6aa1c] 3 coats of surfacer, block once with 320 - 400, then seal and shoot color. Time may not be money, but I sure don't like wasting effort either. :wink:

 

[CNKS]

I have used glaze, don't know that I have an etched in stone procedure, it's what ever I think will work on the item I am working on. The original post had to do with sanding scratches, doubt if Fred got as rough with sheet metal as I sometimes do. Usually when I use the fiber wheel it is because of rust. I now have a good DA sander, it might work with the right grit. Also don't think he was using a true surfacer. 182 would probably cover in Fred's in 1 or maybe 2 sanding operations, perhaps one glaze, I don't know. Point I was making is that all "sandable primers or filler primers" are not created equal. YOu need a true surfacer. You have to pay for quality products.

 

[glennster]

phil, i gotta try that dolphin glaze, we have been using icing at the shop and havent had a problem until the last couple times we got re-supplied from our jobber. the icing is pin holing like crazy. i thought it may be temp related, but we have had a swing in weather and its still doing it. other problem we had was 2- 5 gal pails of lacquer thinner we use for pre cleaning guns got filled from the manufacturer with pre cleano. heres a couple pics of a 64 impala coming out of the booth before wetsanding and buffing. we are getting ready to do a house of color candy fuschia on a honda del sol for a customers daughter. have a 71 javelin-restoration in progress, next week 65 vette coming in. work work work!!!!
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this is diamont base/clear. came out good after it was baked. spent a couple days wetsanding and buffing. its at the engine shop now getting the 409 implanted.
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[PhilC]

Nice job on that Impala glennster, looks mighty nice before it got "detailed". Reminds me of the 63 SS 409/4spd I had many years ago, even had the factory 2x4 package for it but never put it one before I sold the car.

I [i:32077e626e]love[/i:32077e626e] Dolphin Glaze on flat surfaces like hoods, roofs, &amp; decklids, it's just great for them. A little harder to use on vertical surfaces due to its self-leveling properties, but once you've used it a time or two you get the feel for it.

I haven't been very pleased with any other poly finishing filler lately, they all seem to have gotten "thick". We currently use Maxxum Extreme (made by Evercoat) for regular filler and the Maxxum finishing filler. Both products are marketed as a "store brand" and according to the Evercoat rep, they're the same as Rage Extreme and Glaze It. Whatever, they're sales pitches, but the product is very similar to the brand name stuff, works well, and is half the price of the "real thing".

I'll have to snap a few pictures of some jobs I do. I used to do it all the time, but now I just crank 'em out, besides, 99% of our stuff is collision repair anyway, no custom stuff. That's what I built this for....

The big doors were installed yesterday so it's finally weathertight. There's a long story behind the construction of my shop, maybe someday I'll share it. It's 3000sq ft (50 x 60) and 150' out my back door. I'm only going to bust my butt for someone else for maybe another year, then I'm going to work for myself.

Here's a shot of the inside....

Nice storage area for now!

 

[glennster]

nice looking building there fred, you got enough room there to swing a cat!!. we are primarily a collision repair shop too. i bought this shop about 3 years ago after i retired. we take in restorations on a limited basis for our good customers as filler work. i also do some tractors at the shop too. the guys look at me funny, like what the h*ll is that thing. but it sure is nnice painting a tractor in a downdraft booth!!!! glenn

 

[FarmallJoe]

Hey Phil what does somthing like that cost?? did you assemble it yourself, or is it prefabed

 

[PhilC]

Hey Phil what does somthing like that cost?? did you assemble it yourself, or is it prefabed

At the risk of commandeering Fred's original post, it cost me a lot. Wasn't supposed to, but I got scammed by a crooked contractor (so did more than 100 other people in Eastern WA, north ID, western MT, OR, and even AZ). Fortunately, the b*****d is behind bars serving a minimum of 12 of the 18 years he was sentenced to before he's eligible for parole.

In my case, what should have cost $35k per the original contract ending up costing me almost $60k when I factor in the $24k the contractor stole without performing any work. It's a long story Joe, and I don't really want to tell the whole story tonight. Bottom line is, this building could have been built for about $40k if I had not been scammed. What you can't see in the pictures are the 3300ft of hydronic heating tubes run under the slab. Yes, some day, my shop will have a heated floor. 8)

In the end, I had to build it myself with lots of help from family and friends. If you want to browse pictures of the progress, visit this link and check out the photos. If you go by the dates, you can see progress in relative order as it was done.