TheSamba.com :: View topic

Fri Nov 20, 2020 7:46 pm

my first question is about priming. After what grit of sandpaper do you guys start priming? Ive been using 36, 80, 150 and then prime. Some people have said prime after the 80. what say you guys?
My second question is in regards to dollies. Im trying to find a low crown dolly that is good for vw roofs and doors. Ive been using comma and heel dollys and im starting to think I need something a bit less crowned. Anybody got a recommendation or a favorite vw dolly?

Sat Nov 21, 2020 1:31 pm

you use large body work spoons. They 2-1/2 x 6 and have usually a handle. Not too heavy and easy to hold

Sat Nov 21, 2020 4:55 pm

I prime 220 grit scratches. The finer the better. Primer will shrink back and will show heavy grit scratches after paint.

Sat Nov 21, 2020 7:45 pm

For spi epoxy primer they recommend you scuff bare metal to 80 grit, for painting over old paint or primer, then 150 is ok. Pretty much all epoxy primers will have best adhesion this way.

If your using a 2k urethane primer then I'd recommend 150-220 grit.

The higher the grit, the better the adhesion. You just have to apply 2-4 coats which will fill sand scratches, then just sand it down after. If your seeing scratches you didn't use enough product.

Also, before final painting, sand primer with 220, 320, 400/500, 600. Stop at 600 for single stage urethane. For base/clear you go a little finer.

Dolly's come in too many shapes and sizes to name. Many are custom, rare, etc. There are 1,000s of varieties. That is sort of the art of them... there is one for every job. Start collecting :twisted: :lol:

I also would recommend a nice spoon large spoon shaped dolly with a bent handle, those are great for bug roof/hood work.
Such as these:
https://www.ebay.com/itm/Williams-1045-Auto-Body-S...890.l49292
https://www.ebay.com/itm/Vintage-Auto-Body-Heavy-2...890.l49292
https://www.ebay.com/itm/Vtg-Auto-Body-Porter-Ferg...890.l49292

Sat Nov 21, 2020 9:41 pm

Never thought of a spoon. Great idea. As far as priming i was thinking finer is better. I had a guy tell me i should start pring at 80.

Sat Nov 21, 2020 11:42 pm

benchracer1 wrote: Never thought of a spoon. Great idea. As far as priming i was thinking finer is better. I had a guy tell me i should start pring at 80.

Anywhere from 80 to 220. It really depends on WHAT TYPE of primer and what the manufacturer of said primer recommends. Those are the basics. Don't go finer than 220.

I generally like to stay on the grittier side of things, and then apply the primer more heavily, with more coats (as opposed to less coats of more thinned out material) Its makes the adhesion better in the long run, especially for epoxy based primers.

Some of it simply comes down to preference.

Sun Nov 22, 2020 7:21 am

Will you be using a high build primer?

Mon Nov 23, 2020 9:05 am

I generally use the custom shop dtm primer surfacer. I used that spoon idea last night. Worked bitchin. Im going to make another spoon with no handle but a weight on the back

Sun Nov 29, 2020 8:40 am

I used poly primer for my high build and shoot it over 80, but use three thick coats and let it cure for a week so it shrinks back and then block at 180 and finish at 320 dry. I then shoot an epoxy seal coat and then TCP Restorationshop single stage AU.
Every paint system has different requirements so it’s best to read the spec sheet.