I just finished doing my first ever block sanding of SW primer surfacer. Used a long board and paint stick with 180 grit. Sanded quite easy. I didn't press too hard, just enough to show me a few high spots and left a few low spots which show up as shiny unsanded surfacer. My Q1 is should I now fill a few of the "shiny" low spots with a very thin skim coat of evercoat metal glaze Maybe 2 more coats of surfacer would fill the voids, but I'm tempted to skim them now and save on the number of primer recoats. Your thoughts? I am dealing with both doors on my 65 chevelle that I reskinned. The low spots include some depressions making a wavy area along the very bottom of the door.
Q2. Assuming it is fine to use glaze on a few low spots, do I mark the shiny low spot with some sort of pencil, and then sand that low spot hard with 180 grit so the glaze can bit into something. I assume I can't glaze over the shiny urethane primer, or can you?

You might get a couple different opinions on this, but what I would do is like you said, make sure the areas are scuffed, so the glaze will stick, but glaze the entire area...not just the low spots.
Use some guide coat, and block it off again.
Re-prime the entire panel, guide coat, and block again.
If you just try to fill the low spots, you'll end up with craters on each side of it. The glaze, and the area around it,(primer, or whatever) will be different hardness'..if that makes sense, so they will sand differently.
Good luck!
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Zman, is right on the money, apply a skim coat along the whole bottom of the door. Block it flat until it is literally "transparent" as if feathers off.

It sounds like you may be using lacquer primer, is that true? What is the name or part number of the primer?

If it is lacquer, just remember that is the lowest technology and really doesn't fill very good.

Also, when you say "glazing putty" and then refer to "Metal Glaze" you are talking about two differnt things. I know they it is confusing, but "glazing putty" is the name of the old lacquer putty that doesn't use hardener, it is JUNK. "Metal Glaze" is a "polyester putty" and is a totally different product. I know it may sound like I am picking on something pretty small, that I am anal. However, these are two totally different products and you wouldn't want to mix up the two. The "Metal Glaze" or it's sister product "Glaze Coat" are like a ZO6 Vette compared to the Model T lacquer "Glazing putty".

I am using SW Spectra Prime P30 tinted white, as my topcoat will be white. I am told by paint supplier it is latest technology. It is 2 part urethane I believe. I add reducer and hardner, 4:1:1 ratio.I should not have described my other product as glazing putty. It is not laquer putty out of a tube, it must be mixed with hardner. I don't have the plastic container in front of me to get the exact name for you. It comes out blue and changes to a bit of a green blue color when hardner is added, if I recall correctly. Real nice to use.
Another Q. The bottom corners of each door seem to be slightly bent into the car a bit. I can fill this easy with filler to make it flat with the rest of door bottom, but I am considering taking a hammer and banging each corner outward to lessen the need for filler. I realize it is hard to advise without seeing the door, but would you be hammering on the door edge at the bottom corners or just leave it alone and put a skim coat of filler right to the edge of the door, which should make it all flat.

I would deffinitely straighten the door...hammer and dolly the corner where it needs to be first, then maybe a little glaze as necessary.
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I don't know if you read my "Basics of Basics" on door skins, but you certainly can "massage" the edges of the door to make it fit better. In fact, with a careful hand you can usually "massage" the surface around the door to not need any filler at all.

"Basics of Basics" Door skin installation
By Brian Martin

First off, to remove the old skin, take a grinder and grind the edge door where the skin folds around onto the door shell. Grind until you see the three layers of metal. Don’t worry if you grind a little too much, if the shell gets ground a little it is no big deal. On the spot welds you can drill them or grind them, sometimes both. By grind I mean a die grinder with a cut off wheel, just set the spinning wheel on the weld moving it back and forth till you have cut though eliminating the weld.

To prepare the new skin, take a DA or similar tool and sand the OUTER edge of fold in the new skin a little. I am talking about the edge as it will be folded onto your door shell. If you LIGHTLY sand this edge the lip will fold MUCH easier when you install the skin.

If you don’t plan on bonding the skin on, I highly recommend it. It is a corrosion fighter like none other. With the door sitting on it's back (the interior side down) clean the edge where the panel will bond with an abrasive disc to bare metal. Don't use a grinder, it removes metal. Then you will put a small ribbon of panel adhesive, NOT door skin adhesive but the Panel adhesive, it has a higher strength and longer working time. Spread out the adhesive with a plastic spreader so ALL the bare metal is covered. Then apply another thin ribbon on the inside edge of shell where it folds down towards the interior.
I don't know what primer you will find on the new skin, if you can be assured it is good quality and has bonded well, leave it. If it is questionable, then sand it out and apply a good epoxy primer.
After you have a good primer (or left alone) you need to simply scuff it with a red scuff pad down in the area that will be bonding. And believe me DON'T over do it with the bonding! It WILL go around the other side of the fold without even trying and get on your dolly and hammer!
Lay the skin down on the door and position it. Clamp it down at the top where you won't mess up the outer skin. I used a rubber dolly, if you don't have one take a flat dolly and tape a rag or something on it to provide a little cush. A neat home made dolly for this can be fashioned from a 5" long piece of 2x4 hard wood and a 3M rubber squeege glued to it. Hold the dolly on the top surface right over where you are going to fold the lip, strike up on the fold with your hammer while pushing down on the dolly, strike it at an angle so the metal "wants" to hold and NOT lift the skin off the door.
THE TRICK!...... Don't fold it very much at a time, I mean VERY LITTLE, about an 1/8" MAX, maybe even 1/16". Go around the WHOLE door before folding more. Go around and around until you have it folded down almost flat, about 1/16" from touching.
Turn the door over, being particularly careful not to rest the door in a way that will bend your new skin! Now strike down with the hammer while you are still supporting with the dolly to close up the fold a bit more.
ANOTHER TIP!....DON'T smash it down!!!! Two reasons, one you will distort the outside and two you need to leave the bonding in there for it to work.
STILL ANOTHER TIP!.... Use a number of hammers that closely match the shape of the door, if you are in the rounded area at the top of the door, use a domed hammer.

After all folding is done, fine tune the edge so that there are no high or low spots. You can run a vexin file over these areas to spot highs and lows and cut a LITTLE if you need off of high spots. Then using a DA on grinder mode with a 120 disc you "block" the panel around the edge to perfection.

You can spray a weld thru primer on a couple of inches or so at the corners so you can then weld there and not burn the adhesive. But be ready to trial fit the door and twist it if need be for your weld it. You should always trial fit the door before the adhesive cures and “massage” the door to fit well then weld the corners on the back side so the door can’t twist while the adhesive cures.


If you have any fears of not being able to get the door skin on and folded in the working time of the adhesive, don’t use it! All you need is a little tack weld at each corner on the inside at the folded lip. Just go ahead and prime all the hidden areas and after the skin is on, put a seam sealer on the folded seam and spray a cavity wax or underseal around the seam from the inside.


Read the recommendations on the adhesive you are using, some want the metal bare while other want it to be primed, read the tech sheets.

One thing I have been a bit confused on is if there is a polyester "finishing" putty that can be applied right over urethane primer? I was under the impression that all 2 part polyester products could only be applied over epoxy primer.
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You shouldn't have to apply polyester putty over urethane primer. The goal is to have the body work good enough where a few coats of urethane primer will do the job, nothing more needed. This is an easily obtainably goal, shoot for it.

If however you have some MINOR filling, sand the urethane with 180 and skim coat it with polyester putty. Now, the only one I know of that specifically mentions this in the use description is Evercoats "Spot-Lite". It states "may be applied over two part primers". But honestly, I don't see a bit of difference technology wise between it and Evercoats "Metal Glaze" or "Glaze coat" (the exact same product with a different color). But if you listen to me on 99.9% of my recommendations I will say "FOLLOW THE TECH SHEETS". So buy the "Spot-Lite". smile.gif