Newbie advise on minimizing "paint dieback"

[tundraotto]

Hi- longtime lurker, first time poster.

I recently painted my daily driver 93 Toyota Pickup. 3 coats of filler primer, sanded to 400 grit, 3 coats of royal blue metallic, 1 coat of pearl intercoat and 3 coats of clear (last one as thick as I could get it). Paint looks great, but it has dulled quite a bit since I painted it 3 weeks ago. Now it has pretty severe dieback, reflection kind of looks like orange peel, but the surface feels smooth.
I would like your advice on what to do to minimize this. Its not a show car and I have a 4 small runs I will wetsand, but would rather not wetsand the whole truck. Its not a show piece, but I would like to have some serious shine with minimal orange peel effect.

I have:
7424xp
All of the 5.5" Chemical Guys Hex Logic pads
Meguiars 6.5 Yellow and Maroon pads
PC 6" Wool Bonnet
1000 & 2000 grit sandpaper
3M Perfect It 39060 compound
Meguiars M205
Turtle Wax Polishing Compound
3m Hand Glaze

I have never wetsanded or machine polished a vehicle before. Any advise would be greatly appreciated!

[tundraotto]

pictures

[ken tuep]

What usually causes dieback is applying too wet, or too soon between coats. The reducers need to completely flash before the next coat is applied. Fast reducers are more likely to cause dieback because they trap the solvents under the paint.

If I apply 3 coats of clearcoat, I'm sure to give ample flash time before the 3rd coat. If the film build is thicker than recommended by the paint manufacturer, it can cause dieback. I usually follow the manufacturers directions, and dont usually have issues.

Your best bet is to wetsand the paint to open it, and let it outcast for a day or two, then try polishing.
I'd recommend a rotary polisher if you don't have one. A Porter cable will work,( probably taking 3 times longer) but you'd need to finish out with a minimum of 3000 grit sandpaper.

You will have to sand it either way, but it might not completely remove all the dieback, time is gonna be your friend, depending on temperature and humidity.

Me personally, I'd block sand with 600 grit wet, let it dry for a week, and respray the clearcoat.

Perform a test spot on a panel, and see if polishing will work before sanding the entire vehicle down, to make sure you're getting the results you want.

Hopefully this helps ya out.

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[ken tuep]

It definitely looks like the basecoat was wet, when you began spraying the clear. Did you have adequate air flow?

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[tundraotto]

It was 65°F in the garage with the heaters running when I painted, it was 30°F outside. I am sure I did not have adequate airflow. I did extend flashtime (mfg called for 20min, I gave it 30min) and medium speed reducer. I dont have any solvent pop so I think the paint gassed off properly. I think the reason for the orange peel effect is the thickness of the clear coat (especially the last coat).

I really dont want to sand the whole truck....any recommendations on what to do with what I have on hand without resorting to complete sanding?

[ken tuep]

30 minutes probably still wasn't enough time at 65°. I usually like to spray at 75-80° and give a good 20 minutes flash time. The more layers you add, the longer they need to outgas. I'd have taken a lunch break between the basecoat and clearcoat if I was working 65° .



Maybe give a try just polishing a spot, see how it acts.

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[ken tuep]

The 3m polish wont work well with a dual action polisher. The m205 will work, try it on a white pad, and see what kind of results you get.

The dieback is deep in the paint, and more than likely wont polish out. I've never been able to. I usually do as I described above, sand it, and let it outgas more. Then polish it.

Or you could give it more time, and see if warmer weather doesn't help it finish drying.

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[tundraotto]

Well dang it! Thanks for your help Ken - I knew I should have got M105 instead of the 3M....I may get a bottle of Meguiars Ultimate Compound and do that before the M205 and call it good enough......I dont want to mess up wetsanding or buffing and have to start all over. S&%#

[Mike Phillips]

The 3m polish wont work well with a dual action polisher.

I agree, take a read-through this article...

For Use with Rotary Buffer Only - Read the Directions






Do read through the entire article by clicking the link I posted above as it explains the "why" part.

The m205 will work, try it on a white pad, and see what kind of results you get.

I agree with Ken, give the M205 a try with a "polishing" foam pad, not cutting, not finishing.

Slow overlapping passes on the 6 setting, make sure you start out pushing firmly but mark your backing plate so you can see the pad rotating. Pad rotation of utmost importance when using a DA polisher.

The dieback is deep in the paint, and more than likely wont polish out. I've never been able to.

Same here, in most cases the scratches you see in the dieback are under the clear and doing something to the topcoat surface won't affect what's visually under the clear coat. I always test though.

Here's a case of removing dieback...

Here's what Dieback or Shrinkback looks like in fresh paint






This is a close up of the same area that I cropped out at 800 pixels wide but did not resize.






Dieback - After





Before and After




Here's the hood after polishing and waxing...







See all the pictures from this project as well as the products, pads and tools used to get these results by clicking the link below...


How to remove Orange Peel using a Porter Cable Dual Action Polisher

I usually do as I described above, sand it, and let it outgas more. Then polish it.

I like this idea too but I would invest in some 3M #3000 Trizact or Meguiar's #3000 Unigrit and machine sand it.

It's faster and the buff out is SUPER easy.

[Mike Phillips]

I've built my own paint booth in my garage and painted a few cars... not the best option but it can be done...







I put a 454 in this 1959 Caddy...




Going back together...




Sikkens Expoxy Primer