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Fiberglass instead of sheet metal?? pros/cons??

Discussion in 'The Hokey Ass Message Board' started by chopperimpala, Sep 16, 2007.

  1. Thanks for not pitching in with the critics.
    Just remember that if you depend on adhesion to hold to a surface, that large surface area is best.

    Compare the thought of glassing over a round rod; You can usually break the rod loose and pull it out after the glass has cured. Now compare that to gluing with epoxy to a wide flat bar with lots of surface area. The bond is much better, and will stay put even under a heavier loading. You will have a pretty good adhesive bond to it

    Now compare it to this-- This time picture the same part with large surface area, (like above, wide and flat vs compact and round) plus you also have some lumps and bumps on it, and a few carefully placed holes. I don't care whether use a few sheet metal screws to make the bumps in the part, or if you put a few pegs in it or what... Now when you epoxy the part on all sides and glass it in (make sure the glass fibers are embedded or wrapped around and entertwined with the pegs and raised areas to provide the good mechanical grip), you can see that not only do you have the epoxy adhesive-bond to it with a lot of surface for a lot of grip, you have also added a substantial mechanical bond to that.
    Something like a windshield frame or body brace that would normally be epoxied in place at some factories would be even stronger when epoxied and also mechanically "trapped".

    To get something like that loose, you would not only have to break the adhesive bond, but also break the parts into pieces.

    That may be overkill, but that's the way I like to build my stuff.

    Good luck with your new enterprise. Study with good boat builders not the usual car guys.

    Thanks
     
  2. Most definitely, Thanks for the advice man. I need to get started on this project once I get all the current projects done. I am getting anxious to have another 34 Chevy on the road.
     
  3. Frosty21
    Joined: Jan 25, 2007
    Posts: 958

    Frosty21
    Member
    from KY

    My point was, If I had a door corner, cowl vent surrond corner, etc. etc. I'm not going to break out the welded and some tin snips and fabricate some patches that I'm going to have to glass anyway.

    But, as far as taking a unibody car and bondoing the floors together-not a good idea. But compared to some Rust-Belt heating duct metal rivetted into the enormous voids where floor pans used to be on 80's or 90's unibody cars...it'd have to be somewhat better.

    I owned a Chevette that had been in Germany for a while, it had no floor boards on either sides, just pieces of roofing tin with rugs over top of it, car drove fine-but it was a Chevette however.
     
  4. indyjps
    Joined: Feb 21, 2007
    Posts: 4,037

    indyjps
    Member

    back to chopperimpala's question, if the repair is inside the trunk this is a perfect time to learn to weld, its in an area that is not very visible, sheet metal screw or rivet a few pieces together, weld or braze them in. sometimes its difficult to clamp a piece in while working in a corner.
    create a quality repair in metal, it doesnt have to have the same contour as the original, create a good structure for the 3 pieces its supporting and close up the hole. Ive used all kinds of common items to hammer a patch into shape, a few sections of steel pipe in different diameters go a long way.
    Do you have pics of the the area so we can give you advice on a good way to go about the repair
     
  5. PegLegStrick
    Joined: Aug 8, 2007
    Posts: 1,883

    PegLegStrick
    Member




    I agree, I have tried the fiberglass easy fix thing years ago when I ran a Body Shop but quit after several bring backs I had to redo because of the hairline cracks that allways seemed to appear at the feathered edge. Metal is the way to go........
     
  6. 62rebel
    Joined: Sep 1, 2008
    Posts: 2,804

    62rebel
    Member

    i've pulled sheets of metal out of some of my Falcons that had been welded in over the floorboards, and i've pulled out glass patches, patches made of mostly silicone sealant and some made of canned foam. none of them were done right, none addressed the original cause, and were ultimately the death of said car. but those were HACK JOB repairs; no thought of real effort, just a quick "fix" (i really hesitate to use that word) to a right-now problem. the problem with fiberglas is that it has obtained a bad reputation over the years, due to, more or less, the fact that you can buy a can of tiger hair and slop it on your own car. enough joe schmuckatelis filling rust holes in their jersey shore iroc Z's, and the stuff becomes a joke.
    who here has built a car out of plywood? covered with epoxy and 'glass? or been in a homebuilt airplane made of styrofoam and epoxy? don't pre-judge alternative technology just because you don't do it that way.

    BTW the Dehavilland Mosquito, a WW2 British fighter/bomber, was made out of laminated wood panels. HIGHLY successful in combat. i think the glue they had then wasn't anywhere near what we make TODAY.
     
  7. Steelsmith
    Joined: Feb 5, 2007
    Posts: 581

    Steelsmith
    Member

    Some of you guys kill me! Ha

    Being traditional in design is a great standard to use as a goal/target. However, not all cars are going to meet that goal. They either have structural issues that compromise their original specifications or we adapt other suspensions which changes the original design. Some of those design changes work out very well, and are adopted as standard upgrades to alot of old cars.

    Fiberglass/composites are some of the most misunderstood structurally sound materials around.
    Am I advocating building/making repairs to old cars using 'marine resin', (polyester resin)? No, not as a blanket statement. In most cases steel cars should be repaired with steel repairs. Can a steel car be repaired, and a structurally sound repair made using the right composite materials? Of course! It's a matter of KNOWING the correct proceedures/resins/fibers to be used for a given type of bond/repair.

    You won't pick up this type of information at the local bodyshop. Most bodyshops do an acceptable fiberglass repair for spoilers and ground effects. They are not usually trained to do structural repairs, nor are they acquainted with the various uses of different fiberglass cloths, let alone Kevlar or carbon fiber products. The vast array of resins for different applications/adhesion abilities and structural uses doesn't even enter the picture. This doesn't even begin to address the uses of different FOAM shapes as applies to the creation of structure to composites.

    My point here is unless you have definative KNOWLEDGE, don't condemn what you aren't qualified to judge.
    Boat builders have a great deal of information/experience with certain composite structure techniques.
    Aviation builders have an entirely different perspective using a lot of the same or very similar materials.
    It's the application of those materials to a specific environment/usage that makes these various differences in construction. You would not use boat-building techniques to build an aircraft and vice versa.
    You can with sufficient research use a combination of techniques to build structure for automotive applications. Can we use this information to repair a car with 'cancer' in structural areas? Again yes! The only remaining question is, should we? That would depend on the level of skill/willingness to do the needed research to do the job right. Which is determined by using the right materials and the right structure building techniques to replace the original materials with the same integrity in every case, or increased results if the original was a problem child.

    Dan Stevens
    dba, Steelsmith
     
  8. Straightpipes
    Joined: Jan 25, 2006
    Posts: 1,084

    Straightpipes
    Member

    I worked in an industrial fiberglass shop for quite a few years. Then I repaired boats for a few more years. I believe that the use of fiberglass for repairs can be done BUT only with the proper materials, knowledge and experience to use them. As mentioned, you can't just get some matting, cloth and resin and start in on it, it's not that easy.

    Will fiberglass adhere to metal --- Not forever.

    Fiberglass bodies and parts are molded with a release and vacuum process--- whole different ballgame.

    I have a 34 Ford PU and a 41 Ford coupe. I also have a welder and all the necessary shop tools. Niether if these cars has any fiberglass in them.

    Steelsmith is right on.
     
  9. Steelsmith
    Joined: Feb 5, 2007
    Posts: 581

    Steelsmith
    Member

    With properly prepared substrates epoxy resin adheres to metal just fine. Can only be removed by heat or abrasives.

    Composite technology has entered into an entirely new era. Sure there are still some wet layup processes being done, mostly in low end applications like chopper gun applied materials for showerstall/bathtub use.
    You achieve a much stronger result using pre-impregnated cloth applied to both sides of a box section of a cardboard like material. This is then sealed to the mold and a vacuum drawn and held while this is in turn cooked in an oven.

    We, working in our home shops are pretty much limited to a wet layup type of process. That doesn't mean that the end result will be a poor structure, or that there will be a lack of adhesion. It simply means that we will not be able to achieve an optimum ratio of resins to cloth. We can still build good structure, and with some homework we can build a very safe rigid floor or anything else we need for our projects.

    For most of us it's still not the best material to use. Steel is much cheaper as a material. It's the accumulation of other metal working tools that drive up the cost of doing metal work.
    Most all of that can be accomplished using hand tools, it just takes time and skill.

    Dan Stevens
    dba, Steelsmith
     
  10. Sauli
    Joined: Jul 16, 2008
    Posts: 499

    Sauli
    Member

    Your answer is in the "correct" -part of Your text.
    Why not just learn how to use a welder? There´s nothing easy or convenient in working with fiberglass. The supplies and chemicals involved are expensive, messy as hell to work with and seriously un-healthy to be exposed to. PLUS not only that, they make a quarter-ass makeshift breathe-on fix at best. As stated by others already, You just don´t bond these two together permanently, and expect Your patched-up area to be created equal to Your surrounding metal, or for it to last. Especially when You state "this is going to be a daily driver, NOT a show car", isn´t this where Your car will be exposed to the elements and shifts in temperature the most, thus putting the most strain on Your work anyway? SO, why the hell would anyone put in all this time and effort into baking together some fiberglass-infested turd when with just about the same amount of labor and actual thought into what You are doing You could do it right the first time out and actually end up with a permanent fix to boot is beyond me. Frankly, there´s no nice way of putting this, but if basic welding skills are too much to expect of anyone looking to do their "daily driving" in a 60+-yo car they seriously need to find other means of "daily driving", I don´t care what anybody says.

    Whatever ROTH did has nothing to do with CARS, much less functionality of one...

    As far as ´vettes go, they are still steel-skeleton-structure (frame/roof pillar) cars with mere fiberglass panels on top. There´s nothing structural made out of fiberglass in the body of a Corvette.

    And what about the red Studebaker -"baker" who thought there was "nothing to weld new floors into", so "let´s just take a truckload of chicken wire, fiberglass and mud and build an entirely new ones"...(why didn´t the factory think of that, I mean they could have saved a bundle and perhaps never went bust in the first place by never bothering with any of the costly steel-stamping dies...)OMFG, just kill me now...
    Blessed screaming Jesus on a whole-wheat goddamn cracker, hate to say it, but this HAS to be the gayest thread I´ve EVER stumbled across on this site...
     
    Last edited: Dec 25, 2009
  11. tom brown
    Joined: Sep 3, 2008
    Posts: 64

    tom brown
    Member

    interesting debate,most well done metal to metal, glass to metal,cleaned and resined properly will last.every restoration has its own personality. I have seen some rare cars that were so thin with pepper holes saved by glass.ask the purest' how many pounds of skim coat are over those seams and heat wrinkles of the all metal rod? 'also well laminated reinforced glass is stronger than metal.
     
  12. For your purpose it is entirely OK- IF you have good tooth on CLEAN steel. Ive got patch repairs on hood corners that have zero deterioration after 10 years.
     
  13. Hot Turkey
    Joined: Feb 21, 2007
    Posts: 1,237

    Hot Turkey
    Member

    HA HA HA, FIBERGLASS! Don't get me started. Itchy shit!
     
  14. PhilJohnson
    Joined: Oct 13, 2009
    Posts: 906

    PhilJohnson
    Member

    So um did any one notice the date of the OP, 9-16-2007. I'll admit it was an interesting read but why bother posting a reply to an old question.
     
  15. Steelsmith
    Joined: Feb 5, 2007
    Posts: 581

    Steelsmith
    Member

    Yes I realised before I responded to this thread, that it was a resurrected thread from a couple of years ago.
    The question is still a valid one, and I'll do the best I can to answer a legitimate question. Especially one that can be a real safety issue/could risk compromising the structural integrity of a vehicle that has the potential of carrying family/kids.
    Too many cars are on the roads that are not at their best. Most are owned by people who rationalize their short-comings.
    It is my feeling, that we should build the best car that we can. Sometimes that goal is achieved, most times not. We all have limitations either in skills, finances or available materials. We still need to build a car that is as safe as the design allows. Having a composite floor can compromise the entire cars ability to withstand an impact, IF it is not done using the right materials and techniques.
    Would I do it that way? No, probably not. I'm a metalshaper, and have all of the tools to build what I need out of steel or aluminum.
    Somebody else who doesn't have my background, might think they can do a fiberglass floor without KNOWING what they are putting at risk.
    I'm just trying to explain what kind of knowlege is required to do this kind of work and have it be structurally sound. It's not an easy fix, it requires special preperation, and with the cost of composites it's probably not affordable when compared to steel/aluminum repairs.

    Just trying to help answer this question for future builders.

    Dan Stevens
    dba, Steelsmith
     
  16. MengesTwinCustoms
    Joined: Oct 16, 2009
    Posts: 279

    MengesTwinCustoms
    Member

    Nothing pisses me off more than getting fiberglass that DID NOT last out of a huge rust hole with a grinder or torch. USE METAL, water will get under the fiberglass and ruin it everytime cheaper is not always better. If you don't do metal work now, you will be able to once its done right?
     
  17. fordcragar
    Joined: Dec 28, 2005
    Posts: 3,180

    fordcragar
    Member
    from Yakima WA.

    I think that fiberglass works great for a boat or fiberglass repair. I've never seen a fiberglass repair that stood up in a wreck, they seem to peel away or partially away, they don't bend like sheet metal does. I haven't seen that type of problem with parts that were welded on correctly. If you have a small hole or situation like that, fix it with fiberglass, if you want. I wouldn't, I would fix it with steel.

    Anyone that thinks that you can repair major rust damage to the floor and to other structural components need to think about what would happen to the vehicle if it were in a roll over accident. My guess would be that the body would leave the car with parts of the floor still attached to the frame.

    Would you want your family riding it that car? Based on the thinking that it should be okay. If you don't have a problem with that, then maybe you should think about the same question, only this time putting the people that you sold the car to in it. They might not be as forgiving.
     

  18. Does any one think before making obserd comments like this? It does not matter when this was posted. The fact that is was is completely mindless thinking. As are many more of the replys above.

    How is this any different than say a Corvette or a kit car or a glass 32 or a glass Willys. The car has a steel frame like all glass made cars do either oem or aftermarket.


    I just did floor pans in a 60 chev 2 door delivery wagon with the most horible fucking floors ever. The entire time I was thinking POR and some glass would fix this pile right up and work EVERY bit as good as a original floor. If properly preped, a glass repair is as good as any and a lot cheaper to do. The floor pan job was over a grand and the car aint done so what is cheaper? For a car that just needs to work, not be right or "traditional"
     
    Last edited: Dec 26, 2009
  19. Captain Freedom
    Joined: May 6, 2009
    Posts: 262

    Captain Freedom
    Member
    from Upstate SC

    Fiberglass takes too long to dry/cure.
    During that time I could bang-out some new pans/rockers/etc, install, seal, & paint 'em.
     
  20. Dude your mixing the activator in the wrong proportions. Glass sets as fast as you want it too. Just like plastic filler.

    I know some good metal men and I'm not bad my self, but if you can pound out some pans, rockers, ect, install seal and paint them in the time it takes resin to set. Then you know the repair is no better than a shitty glass repair job. Your not that fast.
     
  21. John 79
    Joined: Aug 13, 2006
    Posts: 926

    John 79
    Member
    from Sweden

    Metal is the shit.
    Fiberglass,no no nooo.
    I never ever would have done my rusty truck with fiberglass!

    [​IMG]

    [​IMG]

    [​IMG]

    [​IMG]
     
  22. Captain Freedom
    Joined: May 6, 2009
    Posts: 262

    Captain Freedom
    Member
    from Upstate SC

    I thought it took 24hrs (when mixed properly) ?
    That's what I was told in school. The same guy also said that if too much catalyst is used the thing can catch fire :eek: Just what I heard, really don't know, never use the stuff.
     
  23. theHIGHLANDER
    Joined: Jun 3, 2005
    Posts: 8,117

    theHIGHLANDER
    Member

    There's already a bondo epidemic. This old thread may start a 'glass epidemic! :D

    'Glass is fine when used where it belongs, repairing 'glass. I hate that shit too but not as much as bondo. 24hrs? Sorry but I hope that school is either closed or you didn't retain everything you were taught (don't be insulted, it happens). Never seen fire but I did see smoke once or twice in the cup of remaining resin. It's a heat thing like bondo hardener. Ideally glass should be put over some gelcoat but there's exceptions and practice that work and frankly work well but steel repair isn't one of em. The chicken-fucker, er, I mean chickenwire, no wait, chicken HAWK is one of the poorest examples of craftsmanship you could hope to see, and blatent "crash survival" stories do little to justify how it was done. Then with so many crash stories it's like an old joke I remember. In fact it goes like this:

    A guy wakes up in the hospital after a heart attack to find his wife at his side. "Gladys, I want a divorce." he says. "What!?! A divorce? How could you? When your buisness burned to the ground, who was there to help you? Me! When you lost your parents in that awful crash, who consoled you and stayed by your side? Me! When that flood came in and wiped out our house, who was there to help re-build? Me! Here I am again at your side after this heart attack only to hear that you want a divorce? I wanna know why after all these hardships I've helped you endure make you want a divorce!" He replies, "Because Gladys, you're a fuckin jinx!"
     
  24. PhilJohnson
    Joined: Oct 13, 2009
    Posts: 906

    PhilJohnson
    Member

    Any material or method can be unsafe with someone who is incompetent. Some people will never accept the fact that there are many different ways to do the same thing. If the end product is safe who cares if it is glass or metal repair.
     
  25. Straightpipes
    Joined: Jan 25, 2006
    Posts: 1,084

    Straightpipes
    Member

    HIGHLANDER thats fuckin hillarious!!:D:D:D:D:D
     
  26. nutajunka
    Joined: Jan 24, 2007
    Posts: 1,466

    nutajunka

    All this reminds me of what my brother told the guy who was with my brother's ex-wife, bragging about how he had her now and he didn't. My brother just looked at him and said "I guess it's true, one man's trash is another man's treasure.........................................:rolleyes:
     
  27. Glassed over metal repairs? Sounds kind of hokey to me.
     
  28. Sauli
    Joined: Jul 16, 2008
    Posts: 499

    Sauli
    Member

     
  29. Sauli
    Joined: Jul 16, 2008
    Posts: 499

    Sauli
    Member

    So WTF...?
    You were just talking about a 1960 Chevy Wagon with bad floors 50 yrs into it...Where does it need to be "the day before yesterday" all of a sudden?
    It´s not like mom needs to go pick up the kids from Soccer practice and out to the store before today´s supply of lard on sale runs out...

    This is a hobby, my definition of such is that it´s supposed to be enjoyable.
    Still I´d hate to do anything twice, especially if I knew how to do it once, and make a permanent job at it and not have to worry about it ever again. Like You say You do. I´d also prefer to be able to be proud of my work.

    These arguments in behalf of these hack-job half-ass repairs and what time-savings they supposedly amount to, remind me of a bumper sticker I once saw on a tail-dragging ´54 Caddy wallowing all over the road in Finland. It proclaimed: Only the PISS-POOR need to get anywhere FAST...LOL. Which I think not only applies to driving, but life, making the most of it and making educated, well thought-out decisions at it for yourself in general...
    Just a thought. No panties in a bunch intended for anyone.
     
  30. 296 V8
    Joined: Sep 17, 2003
    Posts: 4,666

    296 V8
    BANNED
    from Nor~Cal

    This reminds me of the paint your car with a roller thread.

    I have a 57 Hawk parts car at work that must have been done by dare to be different. The floors are pealing up like old scabs.
     

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