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Re: Undercoat

Posted: Mon Jan 09, 2012 10:04 am
by Joris Koning
Sebastian,

The interesting thing is that Reutter usually missed a number of areas. As such exterior over spray would still be visible after the car was delivered. I guess I am crazy for duplicating such a detail on my coupe :?

Re: Undercoat

Posted: Mon Jan 09, 2012 10:23 am
by Sebastian Gaeta
Joris Koning wrote:I guess I am crazy for duplicating such a detail on my coupe :?

No t at all!!!

I think it is great that you did this. Defending it to other people gives you the opportunity to explain that it is the "correct" way to do it.

As time goes by and these details are ignored or forgotten, we lose a piece of history.

Re: Undercoat

Posted: Wed Feb 08, 2012 9:08 pm
by Mark Erbesfield
Does anyone know which undercoating WilHoit uses?

Re: Undercoat

Posted: Thu Feb 09, 2012 11:45 pm
by Greg Bryan
I asked John W what undercoat he uses at a tech session he host a couple of years ago. He said, with a wry smile, that it's a proprietary mixture . . .
I used a 3M water based product and was very happy with the outcome, abeit expensive.

Re: Undercoat

Posted: Thu Feb 09, 2012 11:49 pm
by Mark Erbesfield
Greg Bryan wrote:I asked John W what undercoat he uses at a tech session he host a couple of years ago. He said, with a wry smile, that it's a proprietary mixture . . .
I used a 3M water based product and was very happy with the outcome, abeit expensive.
Proprietary my as@#%$s. I would be very shocked if it was not straight off the shelf, but if he is not willing to share his choices oh well. Would have been nice to know. If you want proprietary, go to the roofing supply house and use what they used when new, tar.

edit, Greg, can you post the exact 3M product you used? They sell a number of things and I would like to get it right. I was not impressed with 3M seam sealer that I just used and regret using it. Luckily, I only applied one can before realizing I did not like it. Thanks

Re: Undercoat

Posted: Fri Feb 10, 2012 3:35 pm
by Larry Coreth
So Mark what about the 3M seam sealer didn't you like ? How were you using it ?
I used it some years ago (15+) so the product may have changed since then.

Re: Undercoat

Posted: Fri Feb 10, 2012 4:28 pm
by Mark Erbesfield
Larry Coreth wrote:So Mark what about the 3M seam sealer didn't you like ? How were you using it ?
I used it some years ago (15+) so the product may have changed since then.
It did not flow very well, sort of pasty and clumpy. Also, the coverage was poor. I have used the Wurth brushable and it was ok, but dried out too fast to allow smooth easy application. I have just used some Dynatron Dyna-Pro No. 552 and it was excellent. Bought two more cans I liked is so much. It has a very good consistency and brushes on smoothly. Does not dry out too fast. Smells bad like they all do, due to the chemicals.

this place beat my local shop by $7.00 per can.
http://www.tptools.com/Product.aspx?display_id=1812

Re: Undercoat

Posted: Fri Feb 10, 2012 7:56 pm
by Jim Liberty
I have been using Wurth "Shutz" or SKS Stoneguard Black for many years. I like it a lot. Wurth sells the gun for application as well. Not cheap, but nice texture, and hold up for years.

...............................................Jim.

Re: Undercoat

Posted: Fri Feb 10, 2012 11:57 pm
by Mark Erbesfield
Jim Liberty wrote:I have been using Wurth "Shutz" or SKS Stoneguard Black for many years. I like it a lot. Wurth sells the gun for application as well. Not cheap, but nice texture, and hold up for years.

...............................................Jim.
I own two of the guns and bought some SKS, but had been told lately by a couple of people that they did not like the stuff so I got worried. Thx

Re: Undercoat

Posted: Sat Feb 11, 2012 4:42 pm
by John Willhoit
For the most correct look, use 3M Body Schutz. Once competely dried (several weeks) it is just like the factory undercoat and can be painted with black paint.

The factory used a tar based undercoat before the cars were painted. After painting they brush painted most of the visible areas with black enamel including the engine and front compartments. A correct, original car will usually have black undercoat with the overspray of the original paint color on the underside...not in the fenderwells. All this was hand done and was different on every car. The underside of the dash was also painted black down to the pedal boards. This was usually spray painted but some of the very early cars were brushed.

Most customers wouldn't accept a car restored like this today, and expect things to be over restored.

We have lately begun experimenting with Wurth water based undercoating with very good results. It's a better product than the 3M Body Schutz, and seals out the moisture much better. It's a smoother look that is only original looking on the Twin Grills but provides a much better undercoated finish.

Re: Undercoat

Posted: Sat Feb 11, 2012 9:22 pm
by Bob Lee
John Willhoit wrote:For the most correct look, use 3M Body Schutz. Once competely dried (several weeks) it is just like the factory undercoat and can be painted with black paint.

The factory used a tar based undercoat before the cars were painted. After painting they brush painted most of the visible areas with black enamel including the engine and front compartments. A correct, original car will usually have black undercoat with the overspray of the original paint color on the underside...not in the fenderwells. All this was hand done and was different on every car. The underside of the dash was also painted black down to the pedal boards. This was usually spray painted but some of the very early cars were brushed.

Most customers wouldn't accept a car restored like this today, and expect things to be over restored.

We have lately begun experimenting with Wurth water based undercoating with very good results. It's a better product than the 3M Body Schutz, and seals out the moisture much better. It's a smoother look that is only original looking on the Twin Grills but provides a much better undercoated finish.
John,
Your a good man for not going down the rat hole :wink:
Speaking of rat holes back under my rock I go 8)
Bob Lee
356 Registry member 16135
Porsche 356 Club member
912 Registry member 1588-R

Re: Undercoat

Posted: Sat Feb 11, 2012 9:32 pm
by Mark Erbesfield
John, thank you very much for your post. Great to have your opinions and experience with these old cars. I really appreciate hearing what you have to say about the undercoating. This is one job I only want to do once. I have noticed what you are referring to with regards to different textures. I guess I will stick with my first choice, the Wurth SKS, and see if I can play with the Multi-gun and how it sprays. I did see a product demo on the gun that indicated that it can be adjusted to spray more or less texture. If I can find the video I will post it. Thanks for the help.

Re: Undercoat

Posted: Sat Feb 11, 2012 11:52 pm
by Greg Bryan
Here's the stuff I used on my car and I'm happy with the results altough I am not a concour level restorer - just a hobbyist.
I'll add a picture of the undercoat on my car too (sorry - file size too big)
I case you can't make it out, the seam sealer is 3M 08505 and the shutz is 3M 08804
The seam sealer can be smoothed with a finger until it's blended in and no ridges are visible under the undercoating. The undercoating was very easy to apply in even coats and easy to touch up. The pistol grip was about $80 and every can comes with a disposible nozzle and pick-up - very convenient if you've ever tried to clean a conventional all-in-one body shutz gun. As with all body supplies these days, the stuff is expensive - the seam sealer about $20 per tube (took 5 or 6 tubes if memory serves) and the shutz about $24 per can (18oz) - I think I used over twenty cans!
I think the price is about the same as other makers.
I used a Sikkens product about 20 years ago and still have the gun but couldn't find a supplier in my immediate area. It was good stuff too.
I can email pictures of the applied stuff to anyone interested.
Regards

Re: Undercoat

Posted: Mon Feb 27, 2012 7:40 pm
by Michael Banchero
On my 60 Roadster and 64SC coupe, the Wurth SKS was used and it looks great. Of course the Wurth gun was used. I am sure it makes a difference.
If someone has an extra Wurth gun for sale I might be interested.
michaelb

Re: Undercoat

Posted: Mon Jun 04, 2012 11:09 pm
by Mark Erbesfield
To bring this subject up again. Has anyone experimented with how to get more texture from the Multi-spray gun? I once watched a Wurth demo video that explained how to adjust the gun to get more texture. Can't seem to find it on my computer. Has anyone actually sprayed any tar stuff in the last 20 years? My car is covered in asphaltic material and I can either spend hours removing it from every nook and cranny or just make the repairs and reshoot what was on it. I have removed all of it from the inner fenders, sand blasted and made a couple of minor repairs. Now I need to re-undercoat. Thinking I should just do what the factory did and hose it down with a similar product. Blend it in like Bruce Baker sugessted. Seems like this would be the most original. Not like this car will ever see rain again. Opinions welcome. Thx