Buffing question ?

[NascarFool]

I picked up a Clarke 7" Variable Speed Polisher today. I also got a wool buffing pad and a wool polishing pad. My paint job is far from professional and needs a lot of help. I painted the fenders and hood on Tuesday night, 5 or 6 light coats. I can't remember which because I was pooped when I called it a night. As you can see in the picture, I managed to get a nice shine to come through. Before buffing, I wet sanded half the hood. with 220 grit, 1000 grit and 1500 grit I was constantly spraying water while sanding. The Meguiar's products used were #85, #83 and #80. The shine was not there after using all three products in the order listed. I went back and hit it again with #85 and stopped after the shine came back. What did I do wrong ?

I will most likely need to wet sand with 2000 grit or better due to sanding scratches that are still visible. I buffed it out just to see if my hard labor was going to pay off. By the way, the rest of the hood still needs some major wet sanding before I can buff it out.

[Mike Phillips]

Hi

220 grit and even 1000 grit are pretty coarse for finish sanding, you must be laying on some pretty thick paint?

#85, followed by #83, followed by #80 Speed Glaze should result in a very nice, deep wet shine with good gloss and only the swirls left by the wool pads... I can't say for sure why the gloss would decrease after #85?

Is this single stage paint?

What speed are you running the polisher?

Can you get your hands on two of our W-8006 foam polishing pads for use with the M83, and also for the M80 Speed Glaze?

[NascarFool]

Originally posted by Mike Phillips

Is this single stage paint?

What speed are you running the polisher?

Can you get your hands on two of our W-8006 foam polishing pads for use with the M83, and also for the M80 Speed Glaze?

The paint is single stage. 3rd Dimension HS Urethane Enamel from Sherwin Williams Automotive Paint.

The rotary shows 1, 2, 3, 4, 5 and 6 for the settings. I'd guess that it was between 1200 and 2000 RPM.

I can check the place where I bought the Meguiars products for the pads.

[Mike Phillips]

A couple of things...

First, properly applied and worked until all the diminishing abrasives have broken down, both our compounds, M85 and M84 leave a very high gloss, low swirl finish, to improve upon these results will be more in the area of swirl reduction than depth and clarity reduction which is a testimony to the quality and design of these formulas. This is the reason for switching over to foam for use with the two cleaner/polishes.

Second, if you haven't already, try to watch our video on this topic, you can watch it for free online here,

How to remove paint defects


I also saw it on our eBay auction...

http://stores.ebay.com/Meguiars-Katrina-Relief

[the other pc]

Re: Buffing question ?

Originally posted by NascarFool
…Before buffing, I wet sanded half the hood. with 220 grit, 1000 grit and 1500 grit…

220 grit? Man, that’s rough for an auto finish. Even the “old school” books I have say to start at #400. Meguiar’s Uni-Grit papers start at #1000, Mirka’s Royal Micro papers at #600 (but they tell you to use #1200 and up for auto finishing).

Originally posted by NascarFool
… I will most likely need to wet sand with 2000 grit or better due to sanding scratches that are still visible. I buffed it out just to see if my hard labor was going to pay off. By the way, the rest of the hood still needs some major wet sanding before I can buff it out…

#220 to #1000 is a huge jump. It’s really difficult (and/or time consuming) to remove the coarser scratch when you make that big a grit change in one step. I’m guessing a lot of the sanding marks you’re seeing are leftover from the #220.


PC.

[Five Star]

as far as wetsanding.. wouldnt use anything heavier than 600 grit working your way up to 2000..

then your M-85 to M-83 to M-80


I'm wondering if the M-66 would work well as a one step as mike mentioned in my other thread.

I just switched over to all Meguiar products so i am still experimenting and learning them myself.

[NascarFool]

I'm not sure why the paint is going on like it does. I think it is because the compressor cannot deliver the CFM that the gun needs. Does the brand really make a difference ? Currently I am using ACE Hardware brand paper. This morning I am going to see if FinishMasters is open and if they are I will pick up some Meguiars paper, sanding pads and buffing pads.

Below is a pic of the paint problem that I am trying to fix. I really don't think you can classify it as orange peel or solvent popping. To me it seems like the paint is not atomizing when sprayed. Right now it is just the front fenders and hood, I have put the painting on "hold" until I can figure out the painting problem.

This is an area of the right fender and hood. It is a crop out of a bigger pic with no resizing. Using 400 or 600 takes hours to get the "texture" off.

[the other pc]

Ah, I see.

The orange peel most people talk about around here is the subtle OP you see on OEM finishes. What you have is way beyond that.

You definitely had an issue with the shoot. Here’s Sherwin-Williams Troubleshooting Guide note about OP. If you end up having to re-shoot any areas it would be a good idea to experiment with the gun to improve how the finish lays down.

I hope the paint is thick enough to just do the sanding.

Yes, the brand and type of sandpaper makes a difference. Like any tool different sandpapers are made for different purposes have different results. Hardware store paper is probably meant for general purpose sanding on every thing from wood to metal. I would try to stick with paper made for auto finish work, Meguiar’s, Mirka, 3M, Norton, etc.

Since you’ll have to start with a really course paper you won’t be able to use the Meguiar’s for your first couple of passes but I’d definitely suggest using Meguiar’s papers for the last two or three grits. The uniformity of the grit on Meguiar’s papers substantially reduces the amount of compounding necessary to remove the scratch pattern. You'll have less work and get better results.

I wouldn’t skip grades of paper more than about 2:1. If you start with #220 try #400 next, then #600 to #800 and so on. Not a hard and fast rule but you do need to work gradually to remove scratches left by the previous step. Experiment with a small area to make sure your chosen process/progression works before doing the whole car. A magnifier can really help when inspecting results.

If I were going after that much OP I’d really want to use a DA air sander, much less work and more consistent results. Unfortunately, if your compressor can’t keep up with your spray gun it probably won’t handle the sander either.

Good luck.


PC.

edit: Oops, left out Mirka, should read “stick with paper made for auto finish work, Meguiar’s, Mirka, 3M, Norton, etc.

[NascarFool]

According to Sears, the gun and comp are compatible. I plan to spray some more today and I will test spray on the old truck bed first. Sure can't wait to get this truck finished.

Just for the heck of it, this is what my truck looked like a few months ago.

[Ranger72]

Hell you could have put the paint on with a roller and it would look better than the before pick!!! Good luck getting everthing straigtend out. Just curiouse, how far are you holding the gun from the truck? I wonder if you are holding it too far away?

[the other pc]

Assuming the gun and compressor match OK then it should be a matter of adjusting the pressure, the gun and the paint mixture along with using proper spray technique.

Do you have the instructions for the specific paint product you’re using? If not, here are the data sheets for Sherwin-Williams’ Dimension product line (note that there are many products to choose from, be sure to use the specific data sheet for yours).

Be sure that you drain any moisture from the compressor’s tank and have a mist separator inline with the air hose. Unless the air system is designed around painting (dryers, sub-micron filters, etc.) I would add a deposable cartridge filter up close to the gun.


PC.

[NascarFool]

Originally posted by Ranger72
Hell you could have put the paint on with a roller and it would look better than the before pick!!!

So true ! I'm holding the gun six to eight inches from the surface and aimed straight. Today I'll try a larger diameter air hose. Not sure it'll work but I'm willing to try almost anything.

[Ranger72]

good luck!

[Five Star]

Was the surface properly prepared before spraying? Its hard to believe that spraying it within recommended guidelines it would come out like that unless the compressor was full of water.

I've sprayed SW Ultra 7000 BC/CC before so i could help you with that system.

Good Luck. I'd say just resand it with 180 then 320.. prime it with a good quality primer.. tack it up, then many light to medium coats.. let the primer thoroughly dry. lightly wetsand it with 600 then with a good scrubbing of 2000 grit to get the 600 scratches out. clean it up.. then respray it.

those are pretty much the steps I've followed doing spot blends.

[NascarFool]

Here are the details of the previous painting:

All body panels were stripped to bare metal with Aircraft Remover* and 80 grit on a DeWalt 110v DA. Then sanded with 220 and 320 on the DA. Before priming I used Eastwood Prep Cleaner per directions. Two light coats of Eastwood's grey self etching primer was sprayed. Nothing was painted within 24 hours of priming, therefore I wet sanded with 400 grit (per Sherwin Williams), throughly cleaned the surface, tack ragged it and then used the prep cleaner again. I have tried prep cleaner from Eastwood and Sherwin Williams. After all that was done, I then proceeded to paint. I sprayed light coats and allowed 20 to 30 minutes between coats with no prep work between coats (per Sherwin Williams).

My Craftsman 30 gallon compressor is rated at 8.6 CFM @ 45 PSI and 6.4 CFM @ 90 PSI. The paint gun is also a Craftsman (rebadged Porter Cable). It is a #915531 HVLP rated at 8.5 CFM @ 40 PSI. According to Sears, it will work with the compressor. I have the regulator at the compressor set at 45 PSI (I tried 90 PSI also) and the regulator at the gun has been set anywhere from 10 to 40 PSI while trying to adjust for proper spraying. The air hose is a Legacy Retractable 3/8" x 50'. I have also replaced the 20 oz plastic paint cup with a 3M Paint Prep System cup and liners. The paint being used is 3rd Dimension 3.5 HS Urethane Enamel in Daytona Metallic Blue (Dodge PB4). It is mixed at 8+4+1 (paint+reducer+hardner). I really appreciate the help. Someday my old Dakota will look new again.




*Kinda silly to name it Aircraft Remover. I was removing paint not aircrafts.