tailgate shaving

hey i'm shaving my tailgate handle and emblems off anf i have to fill and smooth.  should i apply mar glass before  or after bondothen sand to what grit?  i will post my pics with my next message.

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Make it Euro'n!!!

Have plugs welded in place. Fiberglass products are not the solution when it comes to steel. Car audio guys will disagree but just ask an experienced auto body guy and you will find that he will agree with me. Marglass is a good product for certain structural purposes but is all to often regarded by car audio guys as the all mighty solution to any problem regarding strength or shrinkage. The fact is that mar glass shrinks 5-9%when curing causing a weak bond to metal that it has no ability to chemically interlink with. Even when properly mixed with the correct amount of hardener and cured at the optimal temp this stuff will shrink a minimum of 5%. Most of that shrinking will occur after the primer, base coat and clear coat cures on top of it. This is where the real problem is. Even if your material dose not crack at the point where it bonds to the metal (at least visibly, at the molecular level it always will) you will find that the material will sink and leave a line around the filled area that shows right through the paint.

I suggest that if having an auto body shop do the welding for you is not an attractive option that you find just anybody with a welder to do it. Even with messed up ugly welds you can do a little grinding (or a lot) and achieve a good metal base on which you can apply your fillers too.
Grind off the surrounding paint and maybe even cut a sheet metal plug your self so that everything is ready for your welding guy.
After the welding is done use Vette filler (made by Evercoat, available at your local auto paint store) to do your body work. Shrinkage is still a problem even when you have a welded plug. Vette filler will drastically minimize this problem.
Sorry to be all preachy but I thought that this info might help you out.
Good luck!

speakermakers,

thanks for the info, but my body shop guy actually uses this product often and i called him yesterday to find this out.  after apllying the marglass, wait a few days and then add a body filler he said.  i catually ground down all the paint so there wouldnt be a noticeable difference.  then i marglassed all the low areas and in a few days i will bondo the rest and sand to smooth.  but thanks just the same, im sure you're probebly right so i will give a few extra days hopefully it will work out as well.  dont worry i dont think youre preachy, just very imformative actually.  i appreciate the help.  just hadnt had a response on here and got anxious.  and wow a little dizzy i didnt wear a mask my bad.   should've done that one in the garage, stupid wisconsin winters.  i'll let you know how it turns out.

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Make it Euro'n!!!

Hopefully you have a good experience with this. I have found and confirmed with a few award winning body guys (they do paint jobs in the 30-50 thousand dollar range) that any polyester based product (Marglass falls into this category) will shrink do to a chemical reaction when it is cut off from the outside air. Even after the product has fully cured. This is why I have in the past experienced the shrinkage problem only after painting. The Marglass will tend to draw towards any source of open air. When I fabricate and end up in a situation where I need to paint over a filled seem I spray urethane primer first then fill then spray more urethane primer over the top. This encapsulates the filler and greatly reduces this effect.
Last year I built a system for Infiion Raceway and Toyota. I had this shrinkage problem but the project still looked great so I shipped it. It seems that I was the only one to notice the flaw but it really bugged me. 6 months later the truck came back because some intern at the track had scratched the living hell out of the paint. So I had my chance to take care of the dips that had occurred do to shrinking and repaint the project. I sanded the dips out (exposing the filler in the process) and sprayed urethane primer then color then clear (I do my own paint work) and low and behold, IT SHRUNK AGAIN!! This is after 6 months cure time and I had not added any more filler.
Later I found out that this is because I had not sealed the material before applying the filler the first time.






As I said before I hope this dose not happen to you. In my line of work I have learned that unexpected failure is not an option so I tend to go overboard on the preventative steps. I think its pretty cool that you are investing the time to customize your ride your self. Keep it up!

What part of Wisconsin are you in? I am originally from Sheboygan.

just throwing this out there because you said you're doing this in the cold... i believe there's a different mixture to hardener when you're working with this stuff in the cold rather than whats just listed on the can. Because the cold keeps it from curing fully.  ... you might wanna throw a heat light on it for a while or i've even heard  of a blacklight. either way in the cold it'll take forever to completely cure.

Thanks for all the input so far guys and/or gals.  to answer all your questions... I'm from waupaca wisconsin(central part) and i actually did this in my basement, thats why i got so dizzy, the fumes built up tooo fast.  oops! i know bad idea.  as for the glass shrinking, i hope it dont now that i already did it before i got ur posting.  it will be at least a good year before i get paint done, as i recently got layed off from my job.  but im getting it primed so it will have a protective coating on it for that time.  so if i notice any shrinkage which im sure will probably happen, damnit.  i will try to fix it then.  so again keep up the input, in the end i know i will learn more and it is helping alot.  a year ago my body shop guy shaved my fender emblems, and did the same process and primed them and it hasnt shrunk yet.  just hoping for the best.  thanks again

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Make it Euro'n!!!

hey where do i look for fiber rod.  i wanna get some for my truck. and how do u get the bends in it and how easy is it to install and work with?

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Make it Euro'n!!!

My favorite store in the whole world. www.tapplastics.com
If it’s still around check out my how to thread under the lighting section of this page. The thread is called “easy lighting method”. I explain how to work with this stuff.

https://www.the12volt.com/installbay/forum_posts.asp?tid=91728&KW=easy+lighting+method