Undercoating question

[Steve Smith]

To those of you who have undercoated an SWB this question is about the SKS Wurth product.

In my rebuild I am going to need to do some more undercoating. Previously I had someone spray the coating with the spray gun that Wurth sells. My question is this. If I use the Stone Guard black in the spray can does it match the non spray can application? I really don't want to buy the gun if I can avoid it.

[edmayo]

No, the aerosol will be smoother,,,sometimes you can 'stick' it with a stiff brush and get some texture. Only the 'gun' can match a 'gun' sprayed texture.

[Bullethead]

IMO buying enough Wurth SKS for a complete job AND the gun is nothing compared to an incorrect finished product. You'll spend roughly $600-900.

The gun is cheap relative to the results. Just do it.

[Steve Smith]

No, the aerosol will be smoother,,,sometimes you can 'stick' it with a stiff brush and get some texture. Only the 'gun' can match a 'gun' sprayed texture.

Thank you for the input.

[Steve Smith]

IMO buying enough Wurth SKS for a complete job AND the gun is nothing compared to an incorrect finished product. You'll spend roughly $600-900.

The gun is cheap relative to the results. Just do it.

That's what it looks like I'll do. I'm trying to match what was done with a gun so I will probably get the gun.

[304065]

Steve, we did this on '065, first did a LOT of research on the car. For example.

1) Look at the spots where the Factory applied tape to mask spots where things bolted up, e.g. the bumper brackets on the inside of the trunk. They literally slapped on masking tape, schutzed the car, then ripped the tape off, and they didn't make a square edge on the tape, either. You will need to study an original car to do this, preferably one that's been disassembled, to see all these tape lines.

2) Study the differences between SWB Factory, SWB Karmann (yours) and LWB undercoating-- you'll notice that the Factory undercoating has a rougher finish. LWB is more like puddles. Karmann is more like LWB-- they really sprayed that stuff on.

3) the Wurth gun is a MUST (as Ed says,,,,, remember I told you,,,, you can take what Ed says straight to the bank,,,,) You will need to spend some time experimenting with the gun as it has adjustments for flow and air pressure and pattern. The gun you want is called the "Underseal Cup Gun" and it's expensive.

3) To duplicate the rougher finishes you hold the gun further back from the surface so that the droplets air dry partially on the way to the surface. They hit and then fully dry, leaving rough peaks. To replicate LWB, you hold the gun closer, and move slowly-- you lay a lot of product down and the air blast from the gun makes puddles in the surface.

Telling you how to do this is not really giving away a restoration secret any more than giving you a box of paint and pointing at the end wall of the Sistine Chapel is an IP infringement on Michelangelo's Il Giudizio Universale. It takes a lot of time and practice to do it right and you must have original cars to compare it to.

4) You will probably want to paint over the schutz to match the gloss. Newly-cured schutz is quite dull.

5) When wet, schutz is BLUE in color. This is normal, it will turn black. Do not panic and try to remove it. Schutz does not like to be removed.

6) Do not wear any clothes that you want to keep while doing the process and wear appropriate respirator and other personal protective equipment at all times.

7) Be sure to use seam sealer first, you can squirt it on with a caulking gun, then go over it with a parts cleaning brush just like the factory.

8) Most important rule when replicating factory schutz is DO IT SLOPPY. That's what they did on the line.

[Steve Smith]

I'll post some pictures here as you guys are giving really good advice. And a little more back info from me.

15-20 years ago when I had the car blasted, rust repaired and undercoated, the company I used didn't quite undercoat a 67 properly. You can see this in the Frunk and Passenger compartment. And just as importantly, being the younger version on me, I decided to keep the color red ( I bought it that way) even though the car was originally Green. The beautiful dark green that was available on these cars in the SWB. So I had them spray red and then coat over it. Years later here we are. I want to take the car back to the green but am NOT going to blast it again and start over. I will have the car until I die and most likely my wife will sell it after I'm gone and there you go. The next owner will just have to deal with the red deep down.

So what I am intending to do is spray all the red green (maybe I should shoot everything green ?) and then under coat it properly in the frunk area and in the passenger compartment. The under carriage and engine area are spot on. It was all done originally with Wurth and the gun attachment. So let's hear some ideas? Paint EVERYTHING green or just paint the exposed red with green and then coat it?

[304065]

I will have the car until I die and most likely my wife will sell it after I'm gone and there you go. The next owner will just have to deal with the red deep down.

And you will be remembered in heaven for 1) painting the car something other than Polo Red; and 2) Painting it BACK to Irish Green 6606.

But I have to admit I am a LITTLE biased in that regard.





I do not know the impact of shooting green over the red, in terms of how many coats it will take to cover. When Damon did '065 it was over gray. Fortunately Irish green is a dark color and not all that transparent, but talk to your paint rep.

The other thing I will tell you is that the "Glasurit" or other stock color for Irish Green has too much gray in it. I have seen the color all over the place-- some cars have too much yellow, some were shot from the Glasurit formula and are too gray. We used PPG on '065. The best way to do it is to scan an original car to get the baseline, then spray out some test cards to get it right. It's unlikely to nail the exact shade on the first try. We did about five test cards as I remember, they were all wrong-- I used to look at them under fluorescent light, bright sun, cloudiy sky, etc., to approximate what the car would finally look like.

I assume you are using single stage, that's what the Factory did. Base/Clear on an SWB looks too shiny, too modern-- you can't quite look right at it.

Anyway on your schutz plan, as long as you appreciate that you're adding weight, it won't be the end of the world, and trying to remove the existing schutz will be a HUGE project. . . maybe the car will be quieter!