Gelcoat vs Dura Tec

[Jim S.]

Hello and Happy New Year,

To all you Painters , and anyone else who has had their car painted out there.

While speaking with my painter , he suggested that rather than Gel coating the body , we use Dura Tec. It is made by Dura Tecnologies. He claims it is just as good and involves a lot less sanding. Hence saving me money,, and him time .

I know that there are pros and cons to gel coating. There are those that would never paint a C-2 without it , and those that claim it is not needed . However, I have an original A/C car, and have read enough horor stories , here and elsewhere, to convince me that it is the only way to go.

My only question is if any one out there is fimiliar with the Dura Tec, and if it is in fact , just as effective in preventing bubbling of the paint ? If so great , and if not, which of the two types of Gel coat is best to use ?

Jim Schwering

[Timothy B.]

Re: Gelcoat vs Dura Tec

Jim,

I am not a painter but I have done a handful corvette paint jobs. If your car has original GM glass I don't think it's necessary.

I understand there will be others that do not agree but with a good epoxy primer to seal everything then sandable primer and a thin coat of sealer before color I think you will be fine.

My technique(sp) may be old compared to what gets done today, I think if you strip the car a piece at a time using laquer thinner to clean the surface everything will turn out fine.

[Mike Z.]

Re: Gelcoat vs Dura Tec

I agree with Timothy! Having done several Corvette paint jobs, and having done research with both PPG & Dupont reps-all agree: unless there has been body damage and/or panel replacement; the recommendation is to get the top coat(s) of color paint off (I have successfully used chemical strip) down to the factory rust color primer (Marine paint strip does not easily penetrate or harm the primer, but I let the striped body sit untouched for a few weeks to make sure all the chemical residue has evaporated and wash a couple of times with mild dish soap then paint reducer). The factory primer is of excellent quality epoxy base-it was the lacquer top coat that was not up to the quality we would like. A seal/primer coat is all that is required over the factory primer and the new top coat will bond with no problem.
As a side note: if panel replacement of repair, I have used gelcoat with great success. I have not tried Dura Tec, but then again I do my own paint & body work so labor cost is not a consideration. Further, with the addition of a new gelcoat, it is very easy to lose the evidence of the bonding stripes, which are desired in a purest type restoration.
Mike Zamora
#12455

[Jim S.]

Re: Gelcoat vs Dura Tec

Mike and Tim,

Thanks for the responses. Unfortunately I do have a replacement pannel (shimmershine's) and I have an original A/C car which has been spitting oil underneath the hood for who knows how long. Also the car has been stripped down to the glass, past the brown primer.

While researching the archives , I found many folks who said their paint jobs started to bubble the first time they sat in the sun ! Many were in the hood area due to the old style A-6 compressor leaking oil . I came across one thread that said ; "old A/C car hoods should be thrown out and replaced before painting". Not wanting to go that far ,and fearing the difference in the replacement pannel, as well as leakage from the MC ,Power Steering Pump, etc etc. I decided not to take any chances!


While I really do appreciate you both trying to save me some time and expense, as no one likes to save money more that I , at this point I am convinced that if a car's paint could start to bubble due to contamination from the back side of the glass penetrating outward, or from a bad replacement pannel, mine would be it ! And being a Metalic color, and me being such a baby, makes it even more imperative that it not happen to me !

So It is down to the Gel coat or the Dura Tec. If for no other reason but to allow me to sleep at Night.

Thanks Again ,

JIm

[Jim D.]

Re: Gelcoat vs Dura Tec

I did a search on DuraTec since I've never heard of it. It is a spray polyester resin. Why not just use Slicksand or Featherfill? It's the same stuff, designed for autobody and used by many on their Corvettes. I use it on every fiberglass car I paint. It is a great sealer.

Jim

[Richard M.]

Re: Gelcoat vs Dura Tec

A good friend of mine in Long Island who has painted dozens of Corvettes over the past 30 years now uses DuraTec exclusively. Another local buddy uses the same. He has been in the Marine industry for years and came to be using DuraTec for a long time in place of GelCoat.

Both swear by the DuraTec product and would never go back to GelCoat. I have also heard that the "Quicksand" product is actually the same polyester resin base as DuraTec.

Rich

[Jim S.]

Re: Gelcoat vs Dura Tec

I did a search on DuraTec since I've never heard of it. It is a spray polyester resin. Why not just use Slicksand or Featherfill? It's the same stuff, designed for autobody and used by many on their Corvettes. I use it on every fiberglass car I paint. It is a great sealer.

Jim

Thanks Jim , I will look into both. Do you think they are as good as Gelcoat , or just easier to handle?

Jim

[Jim S.]

Re: Gelcoat vs Dura Tec

A good friend of mine in Long Island who has painted dozens of Corvettes over the past 30 years now uses DuraTec exclusively. Another local buddy uses the same. He has been in the Marine industry for years and came to be using DuraTec for a long time in place of GelCoat.

Both swear by the DuraTec product and would never go back to GelCoat. I have also heard that the "Quicksand" product is actually the same polyester resin base as DuraTec.

Rich

Rich,

Thats what my painter said also, but it is good to know it is not just his opinion, or that he is using it only because it is easier to work with .

Jim

[Mike Z.]

Re: Gelcoat vs Dura Tec

Tim-sounds like you have received some positive testimonials for the Dura Tec-maybe I will use it on project next if necessary. Say, my Duntov Award 66 is an A/C car and I never heard of the lubricants penetrating from the underside of a panel to the top coat. Having worked with fiberglass since the late 60's, I find it highly unlikely this could occur. It seems the lube would have to first go through the black-out paint, granted not a very good quality paint, then through cured fiberglass, then the gel coat, and factory primer to affect the top coat-just don't see it happening. On my car, painted in 2000 and no signs of any issues, the underside (entire car) was striped, washed with soap/water and rubbed down with paint reducer, then sat for a couple of months before any paint products applied=no problems. I can not stress enough the time allowed to just sit and let the chemicals evaporate naturally-maybe a production shop does not have this ability, and perhaps that's why the bubbling you mention-I think it is imperative for a quality job, but that's just my two cents worth. The bottom line is your painter is probably going to guarantee his work, so let him be responsible for any recommendation and products he wants to use and process to get the job done. I am sure you checked him out and feel comfortable he knows what he is doing, so go with it-Good luck!
Mike Zamora
#12455

[Dick W.]

Re: Gelcoat vs Dura Tec

. . Having worked with fiberglass since the late 60's, I find it highly unlikely this could occur. It seems the lube would have to first go through the black-out paint, granted not a very good quality paint, then through cured fiberglass, then the gel coat, and factory primer to affect the top coat-just don't see it happening. #12455

Mike it is an infrequent problem on AC cars. Over a period of years the oil will soak into the fiberglass and cause problems with the substrates and top coats.

[Wayne W.]

Re: Gelcoat vs Dura Tec

I never heard of the lubricants penetrating from the underside of a panel to the top coat. Having worked with fiberglass since the late 60's, I find it highly unlikely this could occur. Mike Zamora
#12455

It happens and its not that rare of an occurrence. I have seen and dealt with it many times. Jim, just spraying gel coat or any one of the other polyester primers will not solve the problem in most cases. The surface needs to be removed and repaired with fresh fiberglass, then sealed with those products to make sure it doesn't come back.

[Tim E.]

Re: Gelcoat vs Dura Tec

Jim - I used the PPG epoxy primer on the fiberglass of my '66 but did use spray gelcoat back on my '59. In both cases, my results were good but both cars had factory panels.

The gelcoat was a tremendous amount of work due to 2 things: the hardness of the gelcoat and the wax byproduct that migrates to the outside surface. I would use the cheapest sacrificial sandpaper I could find to remove the wax, it would immediately load up whatever grit used. Once I cut through the wax, I could sand normally and apply primer coats as needed. My results were good, but it took extra time (in my case, my time was "free").

I know you don't think I ever do any work on my car (that Carla does it all), so I suppose this picture won't help my case at all.....

[Jim S.]

Re: Gelcoat vs Dura Tec

It happens and its not that rare of an occurrence. I have seen and dealt with it many times. Jim, just spraying gel coat or any one of the other polyester primers will not solve the problem in most cases. The surface needs to be removed and repaired with fresh fiberglass, then sealed with those products to make sure it doesn't come back.

Wayne,

Now you really have me scared. Are you one of the folks that agree with the statement that an old A/C hood should be thrown away, or that a section should be cut out and repaired ?

As to the statement that " fresh fiberglass should be applied and than treated with those products to make sure it doesn't come back ."........ I don't know that I ever had the problem before. As soon as I bought the car I began stripping the paint from it , and only learned of the problem later on , from reading the experiences of others. I than thought that by applying Gel coat one would solve the possible situation . If I read you right, you are saying that if the problem exist , even the gel coat won't stop it ! Is there any way to tell if I do, or will have a problem from looking at a bare hood ?

Jim

[Jim S.]

Re: Gelcoat vs Dura Tec

Jim - I used the PPG epoxy primer on the fiberglass of my '66 but did use spray gelcoat back on my '59. In both cases, my results were good but both cars had factory panels.

The gelcoat was a tremendous amount of work due to 2 things: the hardness of the gelcoat and the wax byproduct that migrates to the outside surface. I would use the cheapest sacrificial sandpaper I could find to remove the wax, it would immediately load up whatever grit used. Once I cut through the wax, I could sand normally and apply primer coats as needed. My results were good, but it took extra time (in my case, my time was "free").

I know you don't think I ever do any work on my car (that Carla does it all), so I suppose this picture won't help my case at all.....

Hi Tim,

The problems you describe with the gel coat are exactly why my painter wants to use the Dura Tec. Hence my first question of " is it as good?" Because even if it is the "pain in the Butt" everyone says it is , I will still use it to solve an even larger problem later.

And, you are correct in that the picture only reinforces my theory !! In fact, I now visualize a scenario where you read a post , ask Carla for the answer , and then post a reply! Tell her I said thanks for all your help so far !

Jim

[Stewart A.]

Re: Gelcoat vs Dura Tec

I'm not sold on the Polyester sealers ? It's very soft and bloody expensive as gold. Although the original primer is not real hard either. Gel coat is tough as nails that's why it's hard to sand does that make sense. So if you want a really hard shell gel coat is the way to go. If you want a soft shell polyester is the way to go. stewy