I have a small section of quarter panel with a tiny bit of wheel well to undercoat after I put that transtar 2K epoxy primer on. Do you recommend anything in an aerosol can for this application? How about a brand?

__________________
84 300SD
85 380SE
83 528e
95 318ic

Depends on what you are going for. Concourse, daily driver or garage queen.

Originally the lower external panels had a PVC type chip guard material which was the same color as the body. It has a slightly dimpled finish.

For your concourse level, a "Shutz" gun would be required.

https://www.youtube.com/watch?v=jxHIp5LIHxc

Garage queen.

https://www.3m.com/3M/en_US/p/d/b40071593/

Daily driver?

https://www.duplicolor.com/product/rocker-guard-coating/

SEM has a few different products which work well.

On my 280C (known as "the truck") I use Evercoat 1348 Low VOC Premium Rubberized Undercoating. It doesn't accept top coat as well as the others but is easy to re-apply.

This is a nice feature as my 280C is referred to by my sons as, "The starship Benzer-prise" as it "Boldly goes where no Benz has ever gone before". Back roads, junk yards, trails, etc. , much like the USPS Express shipping motto, "If it fits..".

__________________
“Whatever story you're telling, it will be more interesting if, at the end you add, "and then everything burst into flames.”
― Brian P. Cleary, You Oughta Know By Now

Thanks, Mike.

I had a small rise in the welded area where the patch is and used a shrinking disc on the outside of the weld joint to draw the metal back into acceptable condition. It ain't perfect but it should cover with a 2K high build primer.

I shot the transtar 2K epoxy on the quarter panel inside and out. I swear, the dust from China made its way to my carport and stuck to that primer.

I'm ready to begin prepping for the high build. I need some more advise on the next couple stages.

It is my understanding that I should sand the existing paint with a 180 grit. While the body is in good shape the black, original, single stage paint is well faded now. I considered blocking it but am kinda leaning toward buying a random orbital sander and a soft backing disc to knock the paint down and give the primer something to bond to. I have plenty of time, is that practical?

What would you do to begin to prep this paint for a 2K high build primer?

What 2K high build primer do you recommend? I don't mind price if I'm getting my money's worth.

Recap:

1. What grit paper to sand to prep for primer and is a RO palm sander good enough to use?

2. What brand 2K high build primer do you recommend?

3. Is exposing a 2K high build primer to outside moisture going to create problems later in the process of finishing this bodywork?

__________________
84 300SD
85 380SE
83 528e
95 318ic

Palm sanders are good to use and are my "go to" tools for minor repairs. They do have their limitations. You have to be careful when "blending" an area because it is easy to create low spots using the coarser grits.

I use an old Ridgid RO sander when I'm going down to metal or removing excess weld or filler ( example https://www.ridgid.com/us/en/five-inch-random-orbit-sander). Crude but effective for "getting into the ball park". The disks are relatively cheap and no need for air or wet sanding. Not worth a crap for any type of decent surface finish but it does leave a good "tooth" for primer. You are past that stage but it is something to keep in mind for other jobs/areas. No lower than 100 grit and I'd recommend 180-220 grit depending on what you are removing.

To prep for the high build, I wet sand using a palm RO such as: https://www.jettools.com/us/en/p/jat-730-5-random-orbital-palm-sander/505730 or it's ilk. 200-320 grit.

Wet sand the high build with the same grits you used for the prep using the palm sander.

Go over the areas with a block sander to your satisfaction. Motor Guard has a good assortment of blocks. They are a MUST for getting the final surface level. You might think you got the surface as smooth as a baby's bottom but I guarantee you the first layer of sealer or color you lay down will prove you wrong. No grit lower than 200, don't go any higher than 320 to ensure toothage.

Between each stage, wash, degrease and tack cloth the surface before proceeding. Dawn dish washing soap is a good choice. Don't use a "car wash" type of soap as they tend to have some kind of "shine-enhancer" which is a form of wax. I use a spray bottle with a blend of 50-50 denatured alcohol and distilled water as a final wipe. Watch out for fuzz left behind if you use a micro-fiber cloth.

I go to Finish Masters for my paint supplies. The counter guys are usually very knowledgeable and they are more up to date of what primers are available. Paint and primer technologies evolve constantly and it's been a couple of years since I was able to do any body work.

Drop a private message to JMK on this forum. He's the paint "guru".

__________________
“Whatever story you're telling, it will be more interesting if, at the end you add, "and then everything burst into flames.”
― Brian P. Cleary, You Oughta Know By Now

I use finish masters too. Good peoples with top shelf quality products. I'll visit the store this week and try them.

I've noticed all the 'Best xxx,' reviews on the internet have turned into an Amazon advertisement making them worthless. They list the Zon's best sellers and of course most of the idiots who are first users of a type of product give good reviews so their opinions are worth about as much as the chinese junk they are buying.

Such is life now, you can buy your chinese junk from walmart, harbor freight or snap on.

__________________
84 300SD
85 380SE
83 528e
95 318ic

The Astro Pneumatics are a decent working line of air tools.

I use the 3M Crystal Bay sanding disk rolls. Finish Masters or any decent body shop suppliers carry them.

Yeah, the Amazon reviews are usually a joke. If I read them, I ignore the five stars, because so many of them are obvious shills, and the one stars because most of those are from clueless people with unrealistic expectations or not the slightest idea of how to properly use whatever it is they purchased.

__________________
“Whatever story you're telling, it will be more interesting if, at the end you add, "and then everything burst into flames.”
― Brian P. Cleary, You Oughta Know By Now

I PM'ed JMK and haven't gotten a response yet. It's possible the mail didn't work or I missed sending it or something. Sent mailings aren't saved in my PM feature.



The garage I planned to use for further body work and high build primer is no longer available. I'm going to have to prime this car under the carport if it gets primed before winter sets in.


I know it will be a struggle to deal with rain and high humidity while shooting the 2k high build but is it possible to do this and have it turn out as a good job?

__________________
84 300SD
85 380SE
83 528e
95 318ic

If you are going to wait awhile before applying a color coat I'd shoot it with a primer-sealer rather than a high build primer. Primers are designed to provide a surface which "grabs" paint. Not exactly what you want if you are going to expose the area to moisture, dust, etc.

You can "rough it in" with the high build primer and spray it with the primer-sealer. When you are ready to apply color you can go back and do all your finish sanding.

The temperature and rain would have the most effect on the job. 2K doesn't really care about humidity but temperature definitely will affect your work. 60-90F is about the range you want to be in.

__________________
“Whatever story you're telling, it will be more interesting if, at the end you add, "and then everything burst into flames.”
― Brian P. Cleary, You Oughta Know By Now

I've shot transtar 2K epoxy on the sections that I replaced and keep it out of the direct sunlight. I'm not taking anything to bare metal. If not for a few of the breaks, ridges and such spots where the primer is creeping through cause by the PO learning to buff with a 7" wool pad, I don't plan on actually getting to metal.

However, I'm going to have to find shelter to do this right. Thanks, Mike. You kept me from wasting a lot of time and money.

Do you recommend any particular brand of 2K high build? You mentioned Finishmasters, how much difference is there between PPG's top of the line and the shop master line from Finishmasters?

__________________
84 300SD
85 380SE
83 528e
95 318ic