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When in the restoration process is it best to wet sand & apply final clear coat

2K views 5 replies 3 participants last post by  Instg8ter 
#1 ·
I just purchased my 1st GTO to restore and I don't won't to mess up or do something stupid. I'm not in a hurry and would value the counsel from the vast forum members on best practices/lessons learned.

The car I'm completing the restoration on is a 1965 GTO coupe. The prior owner started the restore process and has completed the following: painted the frame and under carriage on a rotisserie, powder coated metal parts, rebuilt the engine and transmission, and installed the engine, transmission, fuel & break lines, and suspension.

I'm debating if I should wet sand & apply final clear coat now before I complete the wiring, install the exhaust & radiator, install the interior, install the glass, and install the metal trim? My initial thoughts were to complete the above in the event I scratch the body, I would be able to address any markings by wet sanding the body as one of the last steps in the restoration process. However, a concern one mechanic brought to my attention today is if I wet sand & apply final clear coat later in the process, I would have to cover up many items from the water/white powder produced during this process so its best to get the wet sanding and final clear coat out of the way now.

Thoughts?
 
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#2 ·
I can tell you what I did, and it worked out for me.
1st: body work (including rust repair), priming, blocking, wet sanding prior to paint
2nd: underbody/frame paint, engine compartment paint
3rd: All mechanical work - engine, brakes, suspension, drivetrain, etc.
4th: partial interior - just insulation (I used Dynamat "clone"), fitting of hvac system, brake pedals, accelerator pedal, trans linkage
5th: color coat and clear coat on door jambs, inside cowl and fenders, underneath hood and trunk
6th: install all sheet metal except front bumper and front valance - align panels
7th: clean, prep - then shoot sealer, base coats, clear coats
8th: wet sand, cut and buff paint
9th: Complete electrical system including all wiring, dash
10th: final assembly - remaining interior (carpet, seats, headliner, glass, door panels, etc.)
bumpers, valance, external lights, external trim

That worked for me, but it's sure not the "only" way to do it.

Bear
 
#3 ·
:agree with Bear on the order of progression....i assume the car is completely back on frame, you said nothing about the body being already painted? Is it an older paint job you just need to clear over? New base coat that needs 3-4 coats of clear? If that is the case, after a certain cure window the base will need to be scuffed at the least for the clear to adhere correctly. You will also want to know the type and brand of the paint that he used to assure compatibility with your clear. (remember the early BC/CC factory cars that the clear peeled off the hoods, roofs and trunks in sheets). Give us a little more info on where you are at in the process. If it will just needs one final clear coat i would get it all back together wired and panels aligned correctly, get glass in, leave trim off leave interior for after. wet sand the original clear on the outer shell the jambs and undersides do not need to be wet sanded or buffed and are fine with 2-3 coats of clear. The sanding residue will be washed off multiple times before you are ready to spray the clear during prep (water while sanding, dawn and water then rinse after sanding, degreaser prior to spraying). For best finish you will be wet sanding twice (1000, 2500) more and buffing with another two compounds so no matter what you will be masking stuff until complete. then put the interior and trim on. Hardest stuff to get off is the rubbing compound splatter once it dries.
 
#5 ·
The sequence we used isn't the only way to get it done. If the car's already in paint and the paint is ok, then really that just means you have to be extra careful not to damage it while you're doing the rest of the work.

You didn't say what kind of paint is on the car now though... Be aware that urethane systems have a "recoat window" - meaning that there's a period of time during which it's safe to apply the next coat in the process, and it's possible to wait "too long". What happens if you don't get the next coats on "inside the window", is you don't get the chemical bonding/cross linking between the layers which will probably lead to adhesion problems "down the road". If your car isn't done (all the base clear isn't already on it) then it's important for you to find out exactly what has been applied so far, and when, and contact the paint manufacturer of the materials to find out what the recoat windows are for the materials, and if there's a process for proceeding once the window has expired. Some can be sanded and have another coat of the same material applied, then continue on with the process --- some can't.


Bear
 
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