Sanding Marks After Buffing

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PostPosted: Thu May 09, 2019 7:22 am
This is the first time I've painted anything larger than say a brake caliper.

So I sanded down my sunroof because it needed to be repainted (I stupidly thought this wouldn't be much different than a brake caliper) and I'm using a single-stage paint from a rattle can (I don't have a gun or compressor) which I've used before on smaller things with success.

The problem I'm having is I can't get a really good "wet" coat because the can just won't spray heavy or consistently enough to get one.

So I kind of have a half-assed wet coat as well as I could get it and figured I could sand that down and buff.

So I sanded with 320 then went to 400 and then 800 and no matter what I'm getting sanding marks in my finish. I tried going horizontal and vertical on the panel and got them. So then I went with a cross-hatch and those were even worse.

I was block sanding so I thought maybe a PC would be better so I got some sanding discs and it was better to a degree but now I have pigtails... which of course I have to sand away... which of course leaves sanding marks.

I'm about ready to throw in the towel on this. The sanding discs I got were fairly cheap so my next idea was to get some good 3m discs and try those but am I just throwing away money at this point?

Any advice would be GREATLY appreciated.

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PostPosted: Thu May 09, 2019 7:41 am
Yes.....you will be continuing to throw your money away......you've got little to no build up of "solids" here and the sandpapers just easily eat away and scar the soft 1k rattle can stuff. If you don't have the proper tools/equipment to do it right you have very limited options. Read the "Basics" here in our library and watch some youtube videos of the "real" paint process. At best you might be able to have a jobber can up some aerosol base color and you could used something like the SprayMax 2k products for primer and the final clear but even that's kind of "iffy" for a large sunroof panel. To really get it done "right" just consider taking it to a pro...... "Trying" to paint something like this can burn up a lot of money fast with mixed results......
Metal, wood, fiberglass, we work it all... www.furniturephysicians.com We can restore the irreplaceable!

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PostPosted: Thu May 09, 2019 9:22 am
A search for "rattle can" would produce a wealth of negative comments and problems. I did a quick search and had nearly 2000 hits.

Our sincere hope is that people will come here for advice BEFORE they get in trouble but often it is the other way around.
1968 Coronet R/T


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PostPosted: Thu May 09, 2019 11:25 am
i start wet sanding at 800 and go up to 1500. i dont even know if it would be possible to buff up/out if i stopped at 800 grit.
sanding leaves sanding marks in the finish. each grit leaves a scratch pattern that the next grit refines. then onto buffing.
yes- youd be throwing away money with the 3M discs .



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PostPosted: Fri May 10, 2019 8:38 pm
Well after reading a lot in this forum I'm thinking I'm going to invest in a compressor and a standard (non hvlp) paint gun.

For this small of a panel I'm thinking it should work. Unless you guys think I should still take it to a pro.

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PostPosted: Sat May 11, 2019 4:59 am
The only way I would invest in ALL the equipment to refinish it properly yourself is, "If you plan to make auto restoration / repair a long term hobby or career". Other wise, save a lot of money, time , and aggravation and take it to a pro.

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PostPosted: Sat May 11, 2019 6:22 am
Lenny pretty much reflects how most of us feel about this here....unless you have several thousand dollars burning a hole in your pocket, just start shopping around for a local pro or at least neighborhood paint guy.
Metal, wood, fiberglass, we work it all... www.furniturephysicians.com We can restore the irreplaceable!



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PostPosted: Sat May 11, 2019 6:52 pm
I have to say I feel like you guys are pretty discouraging to someone like me who does want to try this out.

Obviously I want to, otherwise I wouldn't have even attempted to do it in the first place.

I understand you guys are all pros and everything but there are those of us out there that want to learn and try.... just because we don't do this for a living or want to open a paint shop doesn't mean someone shouldn't at least try no?

I've read a lot of other threads on here in my research and elsewhere and there are some encouraging folks who understand that one doesn't have to be a professional or plan to be a professional to do this as a hobby or for... God forbid... fun?

I've found a good compressor that puts out over 8 cfm at 40 psi and a gun that is rated for 3.5 cfm at 40... it didn't cost me thousands either... it was a few hundred.

I went to a body shop today and showed them what I was planning to do and they were actually VERY encouraging. They showed me how I would need to mix the paint, showed me what to use to sand before paint, and even gave me some sanding blocks and filters.

Now these guys actually had a financial interest in telling me NOT to do it. But they were really cool and said for "that small a panel you'll be totally fine with the compressor you're looking at."

So... maybe I found the wrong website here... or maybe you guys just decided because I tried to use a rattle can that I wasn't worthy of trying anything else? I don't know... but I'm going to try and if I screw it up... then I'll try again.

Thanks for the advice.

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PostPosted: Sat May 11, 2019 9:19 pm
Most of us are not professional painters as we only paint a car once or twice a year. We started out just as you are but realized this was more than a one time paint job or repair.

The advice is not meant to discourage but to open newbie's eyes to the cost involved to do things the right way.

I too thought I could get by with a smaller compressor and wasted a few hundred dollars on what I thought would be adequate. I also bought a cheap spray gun thinking one is just as good as another. In both cases I was wrong and ended up buying a bigger compressor and better spray guns. Of course the crap I bought to start with had no resale value so in reality I bought two compressors and 4 spray guns before getting set up properly.

Wanting to help others avoid the costly mistakes I made when starting out, I wrote an article: https://www.autobody101.com/content/art ... ould-know/

There are all kinds of "how to" Sticky Posts and articles in the Info Center. They are there because we desire to help.

What becomes a bother at times is when we give someone advice because they asked for it and then they disregard the advice they received.

You were told to seek a professional because you had already tried your way and failed. Thinking this was a one time repair, you were told it would be cheaper to have someone do it for you - that's good advice.

Now if you plan on getting into this as a hobby or you want to do a full restoration on a car yourself, the advice is buy good equipment the first time so you don't have to buy everything twice. That's also good advice.
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PostPosted: Sun May 12, 2019 8:55 am
Imatk wrote:I have to say I feel like you guys are pretty discouraging to someone like me who does want to try this out.

Obviously I want to, otherwise I wouldn't have even attempted to do it in the first place.


we arent ALL pros. i would be considered a hobbiest. ive painted about a dozen cars and trucks in the last 11 years. dont quite a bit of body work on a few of them,too. prior to 11 years ago i had done a LOT of wrenching on cars/trucks but no body work or painting. i didnt know crap. didnt even paint the first car- did the prepwork and buffing afterwards. all of the steps for both i learned from people that had done it. didnt go out on my own. when it was suggested how to prep the car (96 ragtop mustang) for the best results, i did it. when suggested how to color sand and buff and what products to use, i did it.
that was my sons car- a car he had me pick up while he was doin a tour in iraq. had it all finished when he returned. his step dad has been a painter his entire life- worked on the line for ford, worked in collision shops, then went on to restorations. he looked the car over witha fine tooth comb and was very impressed with the results. he was one of the people i got advise from.
this was a southern car. the hood,trunk lid, bumpers and tops of fenders had real bad fading and CC failure. took those areas downt o bare metal because people told me to and why i should.
he sold the car 5 years later when he got stationed in colorado. he said he got lots of compliments on it over those 5 years and the finish was still great.
AFTER that was when i started investing in equipment to paint myself and i didnt start with a vehicle being my first paint job.i spent probably about $1500 on compressor(used),guns, filters, and more of the supporting cast. about another $1000 over the years on the supporting cast. painted a lot of smaller things and learning how the products work.
the truck is one i painted about 6 years ago. my personal favorite. 235k miles on it at the time. new rockers, lower door skins, and a cab corner added.
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