New Problem, Paint

[Terry NJ]

I was sanding my lil' heart out tonight. I was using 400 wetordry, wet and I was working on an area , actually the left rear corner of the body (Later the RR corner) where there was some orange peel. Before long, the primer started to come through. SHEEET! This means more painting! Dammit, I thought I was done with the spray gun. Needless to say, but I will, continue sanding it to capture all thin spots in one operation. Now, How does one do this? Tape off the bad section, spray it and sand the tape ridges down? Or try to "Blend" it in? or is there another way? Thanks in advance.
Terry

 

[tinman080]

What kind of paint do you have on it, 2 stage or single stage? Lacquer, polyurethane. or enamel? Hardener in it? What color?

 

[tbirdtbird]

you need to re-shoot the entire fender else you will always see the transition.
There should be 3 coats of color, and then start the buffing process which begins with 1000 grit, then 1200, etc.
So, you will need to shoot 3 full new coats.
400 is way too rough to use on finish paint. Even on primer...the roughest we ever use on primer is 600 wet.

Each coat gives you about 1 mil thickness. In the process of buffing you will remove about 1 of those layers

 

[pgerhardt]

I was sanding my lil' heart out tonight. I was using 400 wetordry, wet and I was working on an area , actually the left rear corner of the body (Later the RR corner) where there was some orange peel. Before long, the primer started to come through. SHEEET! This means more painting! Dammit, I thought I was done with the spray gun. Needless to say, but I will, continue sanding it to capture all thin spots in one operation. Now, How does one do this? Tape off the bad section, spray it and sand the tape ridges down? Or try to "Blend" it in? or is there another way? Thanks in advance.
Terry

Welcome to my world!! Color sanding through the color coat is my specialty! It took many resprays before I got my doors finished (picture 1). But in my case I am using acrylic lacquer which blends easily. I use an airbrush to touch up the sand through areas, and a mix of 90% slow lacquer thinner and 10% clear (picture 2) to do the blend (also applied with the air brush). The respray boarders are invisible.

Urethane Enamel can be blended with this stuff (picture 3), but it is very expensive - about $100 a gallon.

 

[tbirdtbird]

Blending to invisible is a special skill/art. That is why I did not mention it.
Most find it impossible.
You should be pleased that you were able to make it work!

 

[Mitch//pa]

400
I would have went with 1500. Especially with cheapo paint

 

[pgerhardt]

Blending to invisible is a special skill/art. That is why I did not mention it.
Most find it impossible.
You should be pleased that you were able to make it work!

It helps that the doors were laying flat (no worries about runs or sags) and that it was lacquer, which remelts and merges together easily under the slow solvent.

 

[pgerhardt]

400
I would have went with 1500. Especially with cheapo paint

My last two wet sanding papers are 3000 and 5000 grit! They are both available on Amazon, are mounted on a foam backing, and do a wonderful job. I start to get a nice reflection before I even start buffing!

 

[BRENT in 10-uh-C]

Welcome to my world!! Color sanding through the color coat is my specialty!

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[Terry NJ]

Mitch, this ain't "El Cheapo" paint, it's PPG Shop Line! Cost me, with thinners and hardeners
over $350. I know you can get more expensive paint, but it was over $100 @ Gal. Boy I'd like to know what was in that gallon can that makes it worth that! What chemical, what pigment? Oh yeah, and BTW I was using the 400 to knock the orange peel down. I had it just about where I was going to switch to 800 when I discovered I had gone through.
Terry

 

[Terry NJ]

Tbird, My problem is that I'm not a painter. I TRY to paint and it's probably on thick and thin. The paint colors are the "Drabs", Chickle and Copra. As I said, I got a lot of orange peel and I was sanding it out. And it's the rear of the body and if I had Brent's "Rotisserie" I'd just rotate it to a flat position, but Alas, fate did not issue me one. Und so, I gotta do it the hard way.
Terry

you need to re-shoot the entire fender else you will always see the transition.
There should be 3 coats of color, and then start the buffing process which begins with 1000 grit, then 1200, etc.
So, you will need to shoot 3 full new coats.
400 is way too rough to use on finish paint. Even on primer...the roughest we ever use on primer is 600 wet.

Each coat gives you about 1 mil thickness. In the process of buffing you will remove about 1 of those layers

 

[BRENT in 10-uh-C]

Mitch, this ain't "El Cheapo" paint, it's PPG Shop Line! Cost me, with thinners and hardeners over $350. I know you can get more expensive paint, but it was over $100 @ Gal.

With PPG's better quality paint, you will see a cost of about $75 a sprayable quart. What is in the good quality paint is good quality materials & pigments. Why is Mobil 1 or Castrol Edge oil $9.00+ a quart when Coastal Oil is $1.29 a quart? Oil is oil isn't it, ...and surely an engine should last just as long with the $1.29 oil over that (overly) high-priced oil!!


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Tbird, My problem is that I'm not a painter. I TRY to paint and it's probably on thick and thin. The paint colors are the "Drabs", Chickle and Copra. As I said, I got a lot of orange peel and I was sanding it out. And it's the rear of the body and if I had Brent's "Rotisserie" I'd just rotate it to a flat position, but Alas, fate did not issue me one. Und so, I gotta do it the hard way.
Terry

Terry, a rotisserie really would not have helped you one bit to have a better job. For that, it just takes experience, ...and experience is something you get AFTER you need it!! You now have gained some experience on knowing how to mix paint properly (thinner??), and you now know how to apply it more evenly and consistently. You also know which sandpaper to use at what given time. By the time you get to your 3rd or 4th restoration, you will have all of this down to a science!!

.

 

[Mikeinnj]

Mitch, this ain't "El Cheapo" paint, it's PPG Shop Line! Cost me, with thinners and hardeners
over $350. I know you can get more expensive paint, but it was over $100 @ Gal. Boy I'd like to know what was in that gallon can that makes it worth that! What chemical, what pigment? Oh yeah, and BTW I was using the 400 to knock the orange peel down. I had it just about where I was going to switch to 800 when I discovered I had gone through.
Terry

Terry,

Is that "Shop Line" a base coat/clear coat paint or is it one stage enamel.

PPG is expensive. I recently paid $150.00 a quart for their acrylic lacquer.

 

[Capt Quahog]

Actually, the Model A Ford we've got appears to have been painted with some form of cheap house paint over bare metal with no primer at all. Seems to have been on there for a very long time. Much of the finish is still in place with bubbling and flaking. The effect is a not too offensive, "we could care less". . . "Shabby Chic' " look

 

[pooch]

you need to re-shoot the entire fender else you will always see the transition.
There should be 3 coats of color, and then start the buffing process which begins with 1000 grit, then 1200, etc.
So, you will need to shoot 3 full new coats.
400 is way too rough to use on finish paint. Even on primer...the roughest we ever use on primer is 600 wet.

Each coat gives you about 1 mil thickness. In the process of buffing you will remove about 1 of those layers

I had to google mil, we do not use that term here in OZ.

Found out it is 1 thou or 25.4 microns.

 

[pooch]

I was sanding my lil' heart out tonight. I was using 400 wetordry, wet and I was working on an area , actually the left rear corner of the body (Later the RR corner) where there was some orange peel. Before long, the primer started to come through. SHEEET! This means more painting! Dammit, I thought I was done with the spray gun. Needless to say, but I will, continue sanding it to capture all thin spots in one operation. Now, How does one do this? Tape off the bad section, spray it and sand the tape ridges down? Or try to "Blend" it in? or is there another way? Thanks in advance.
Terry

Sand the whole panel down to smooth at 800 wet finish .

Spot paint where you see primer with thin coats overlapping each coat a bit further as if you doing a spot repair.

Then blow over 3 more thin coats over entire panel.

It only takes a few more drops of thinners to thin enamels over normal consistency, so don't overdo it .

Hope you mixed the paint/hardener properly the first time....or you could have dramas.

The reason for thin coats is you don't want up to 6 full coats of finished enamel on, or a stone chip will look like the Grand Canyon.

 

[Terry NJ]

Pooch, You're scaring me! How perfect does the mixing have to be? A couple of thin lines on the mixing cup more or less? Because I might be in for those "Dramas". What shape do those Dramas take? what should I look for? Oh God! Out of the frying pan into the fire! Maybe!
Terry
QUOTE=pooch;1288794]Sand the whole panel down to smooth at 800 wet finish .

Spot paint where you see primer with thin coats overlapping each coat a bit further as if you doing a spot repair.

Then blow over 3 more thin coats over entire panel.

It only takes a few more drops of thinners to thin enamels over normal consistency, so don't overdo it .

Hope you mixed the paint/hardener properly the first time....or you could have dramas.

The reason for thin coats is you don't want up to 6 full coats of finished enamel on, or a stone chip will look like the Grand Canyon.[/QUOTE]

 

[tbirdtbird]

you said you were getting ready to switch to 800 grit.
Still way too coarse. Throw that 400 and 800 away now before something else happens.

I do not share pooch's concern over paint thickness. At all. I have painted more than 50 cars, trucks, and motor homes, and done countless spot repairs and blending.
By the time you have properly prepped the existing color, or what is left of it, there will be very little paint on there. If you fail to use 3 fresh medium topcoats once again you will NOT have enough thickness to buff, and you will get to do it yet again.
When you paint we assume that you overlap each pass by 50% with the next pass. That is NOT considered 2 coats; that is how one coat is laid down. We assume you are using the fan and not over-reducing. Some ppl over reduce to stretch the paint because they do not want to ante up for the proper amount of paint. You will effectively end up with only 2 coats worth of paint if you do this.

As far as cost, take comfort knowing the markup in the paint industry is over 300%. Now, don't you feel better already
I don't
With dark colors, your first grit s/b 1500, progressing to 3000. Wet, obv.
Use a DA, and keep it moving at all times. Use a flood of water, you should be getting soaked yourself. . Stop often and wipe dry so you can see just how much orange peel you are removing. Put one drop of dishwashing detergent in your water bucket.
Be sure to change the water out whenever you go up to the next grit.
Be sure to use the soft 3/8 foam interface pad on the DA, never use the hard DA pad surface directly.
If you do not have a DA do not paint.

Be very careful around openings and edges, else you will go thru immediately. For example, on a Roadster, the hole in the body where the top rest post screws in, avoid that hole altogether, go around it, and stay about 1" away from it. Yes there will be some peel left there, but NO ONE will see it. Buffing is all about fooling the eye.
You may be surprised to learn that you need not remove 100% of the peel. If you remove 90% by wet sanding, and then go to machine polishing, I promise the eye won't catch it. OK to remove 100% if you are skilled and experienced, but then you are at the point of no return

 

[pgerhardt]

Pooch, You're scaring me! How perfect does the mixing have to be? A couple of thin lines on the mixing cup more or less? Because I might be in for those "Dramas". What shape do those Dramas take? what should I look for? Oh God! Out of the frying pan into the fire! Maybe!
Terry

Here is a tip for you: Figure our the correct fill lines you will need on your mixing cup for the correct ratio and amount while looking at the tech sheet for your paint and mark those fill lines (and label them: paint, thinner, hardener) with a sharpie before you go to mix. That will assure you get the correct mix and remove all the stress from the mixing process.

 

[pgerhardt]

...and experience is something you get AFTER you need it!!

Now that is a wise statement!!! It applies to all skilled tasks, and the worst part is that if you don't do all the time I find you loose it and have to start back at the beginning!!