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Fiberglass & bondo for skim coating?

16K views 54 replies 7 participants last post by  69 widetrack 
#1 ·
i have been using fiberglass on big rust areas after i cover area with sheet metal and pop rivets does metal under fibglass rust?
You cant use fiberglass to patch metal. I cant tell you how many cars ive restored that the fiberglass has de-laminated from the metal. There two different substrates that expand and contract at different rates also causing body filler to eventually crack.
My advise would be to have a competent metal man do the patch for you, Please dont destroy a car by using pop rivets. thats the kind of workmanship that everyone always shakes their head at and laughs. Its not a way to repair a car that you actually like.
 
#2 ·
I'm glad that you started this thread....I'm a little tired of questions like "which is better to repair rust holes, long strand fiberglass or short strand fiberglass". The answer for anyone reading this thread is NONE OF THE ABOVE. I used to try and answer these threads and persuade the OP to not use either and repair it properly by replacing the metal. Too many cars like Mustangs, Camaro's and all the other cars that could have been brought back, are only cosmetically repaired, look good from 50 feet away and 6 months to 2 years later they need to be redone properly but it cost to much because now you need to redo the previous work.

I can't impress on the people that are doing this type of repair that your damaging the car more than bringing it back to life...do it properly, (if it takes you an extra year or 2 to save up the funds that's OK) or don't do it at all.

Ray
 
#3 ·
I agree..;)
Do it right the first time around.. You will be much happier in the end... It takes just as long to weld in new metal as it would to use the filler.. I hate to see people use fiberglass on metal..Big nono..:nono:
 
#4 ·
I can see both sides to this coin. There are all different levels of expectations first off, what are your expectations? What is your budget? What are your skills? What tools do you own?

I believe in doing things the "best" way possible, but then there is also the "bestest" way :D That is doing it the best way you can when the expectations, budget, skills and tools afford you.

There are times when you can "properly" do something without doing it the best way. I know that sounds stupid because if you aren't cutting out and welding in new metal how could it be done "properly" but think about it as doing it the "Bestest" way.

If you sand blast and epoxy prime a floor that is full of small rust holes and then cover it with fiberglass cloth filling all those holes and giving it some strength, it isn't the "best" way but it could be (this is all opinion of course) the "Bestest" way to correct the rusted floor if this meets your expectations than all is good right? In visiting forums over the years we have seen people with all kinds of different expectations. So how can I give them what they need to meet their expectations has been a question of myself.

To answer that question I have tried a few of these methods of repair like testing the 2K aerosols and things like that. So on my Rambler I had a swiss cheese floor board on the drivers side. The interior was all in there so cutting the floor board out and welding in a new one would have taken quite a bit of work. I decided to do it the "bestest" way as a little test. I spot blasted the floor using my "Speedyblast" with the little sand catcher so the sand doesn't go all over. I then brushed epoxy primer on it and then laid fiberglass cloth over it putting a number of layers and then brushed epoxy over that. That was two years ago and driving it every day, I just pulled up the carpet to check the brake fluid the other day and it looks as good as the day I did it.

This is a far cry from pop riveting a patch panel on a quarter panel which is just plain wrong anyway you look at it. But there is a place for these fiberglass or reinforced filler products is all I am saying.


Brian
 
#5 ·
Thanks for the lesson.. But if you put fiberglass on metal it can very easily be pulled right off the metal... Sorry YOU can't make me blieve that.. Under your carpet yes it will stay until it pop's off..... But with what they have out there today,, It's to easy to do it right,, Not bestest...:nono:

If your going to tell someone how to do it... Tell them the right way...You don't have the tool's to do it right,, Then buy them or bring it to someone that does.. My God !!!:drunk:
 
#9 ·
Brian: :D

That was a great post! LOL I'll add this: There are 2 different resins for doing glass work "Finnish resin and laminating resin"

Laminating resin (Evercoat # 100560, 100561) is used for initial coats on wood & metals or for multiple applications with fiberglass cloth or mat. This resin is air-inhibited which means it will cure to a tacky finish and does not require sanding between coats. This is desirable in laminating because the layers adhere to each other better. This product should not be used as a final coat unless measures are taken to seal out the air during the curing process. It is also excellent for overhead and vertical repairs, Because its sticky and will hold the next layer of cloth in place!!!

Most parts stores only sell Finnish coat resins, and lamination is not as good!!! Its called Finnish coat because that's exactly what it is, a Finnish coat to go over the laminated layers!


I've seen so many people using resins that have never heard of laminating resin!!!!!! and then complain because their repairs don't last!!!!

I like that "Bestest" Brian:thumbup: LOL!!

Jester
 
#10 ·
That is a very good point, I was brought up calling it "A" coat and "B" coat. From what I remember the "B" coat has wax in it that rises to the top.

Brian
 
#11 ·
Yep, The laminating resin is non wax!! A and B coat I learned it that way at greenfield village garage 45 years ago! I also laminate Kevlar and carbon fiber! Compound bows were laminated layers and were very strong! If you used Finnish coat to laminate the layers and pulled back the bow you would take your head off! LOL:D

Jester:thumbup:
 
#30 ·
Vinylester resin, Formaldehyde Resin ETC cant forget those! There is also a different coating on the glass fiber for the different types of resin your using so the resin can bond to the glass or other fibers!

No difference in the non waxing and waxing resins, :drunk: There's a big difference LOL, Or there would only be one formula! Like the cheep general purpose economy resin cut rate shops use! And if your doing overhead or vertical work your large areas of woven cloth or mat would fall or slide off!

Laminating resin dries tacky! You don't sand laminating resin, Its tacky to hold your next layer in place and to aid adhesion when applying more layers and helps the Finnish coat adhere to it and the product or repair dries hard and can be sanded or prepped or jell coated!

A lot of custom parts are built using epoxy resin. The issue is efficiency and cost. Epoxy, though a superior technology, costs 2 to 3 times as much as polyester resin and it must be washed between layers,polyester laminating resin needs no prep between layers! Both Epo. and Poly. resins can be used to mold fiberglass, but polyester is more controllable by the amount of catalyst added so production time is reduced- get the finished part out of the mold and get another one started. Epoxy resin is used to make the molds that polyester resin fiberglass parts are made in though!

Epoxy molded fiberglass must also have a surface finish applied! So Polyester resins are used for this! First gel coat the mold and then the laminated layers added and out pops a shiny new part.

249 polyester resin, it drys clear as water, other polyester resins have a blue or green tint

vinyl ester resin is stronger/tougher but is not as clear so not used much with color tinting or carbon fiber.

epoxy resin is the strongest and bonds better with automotive plastics. When using it with carbon fiber it must be U.V. protected in sunlight with a good non yellowing clear. Epoxy is no good for any kind of heat and it will become rubbery at a low temp. It does resist spider cracks but isn't as flexible as polyester resin.

I can apply heat to a Corvette top, rear, front fender corner and apply pressure to get it back in position apply cold and it will stay there! you cant do that with epoxy resin parts!

Jester
 
#13 ·
This may help some of you beginners out there reading this thread !

Jester:thumbup:


After using the laminating resin (Evercoat # 100560, 100561) Use one of these final coats Depending on the perticulars of the project!


Waxing resins: Also called Finnish coat.
Marine and Fiberglass Resin (Evercoat 100552, 100553, 100554, 100517, 100518, 100519, 105498, 105499, 105501 and 105502) are non air-inhibited or waxed resins. They are for the final coat. This resin cures with a hard, non-tacky surface. When the catalyzed resin is applied as a final coat to the laminate coats of resin, the wax rises to the top, sealing off the air and allows the resin to cure to a hard finish, which can then be sanded, painted or gel-coated.
NOTE: Cannot be used with aluminum, redwood and/or close-grained woods like oak or cedar. For redwood, cedar, oak or other oily or close grained woods, Evercoat Everfix Epoxy (100642, 100643) will provide the best adhesion.
Do not use with Styrofoam.
 
#15 ·
This may help some of you beginners out there reading this thread !

Jester:thumbup:


After using the laminating resin (Evercoat # 100560, 100561) Use one of these final coats Depending on the particulars of the project!


Waxing resins: Also called Finnish coat.
Marine and Fiberglass Resin (Evercoat 100552, 100553, 100554, 100517, 100518, 100519, 105498, 105499, 105501 and 105502) are non air-inhibited or waxed resins. They are for the final coat. This resin cures with a hard, non-tacky surface. When the catalyzed resin is applied as a final coat to the laminate coats of resin, the wax rises to the top, sealing off the air and allows the resin to cure to a hard finish, which can then be sanded, painted or gel-coated.
NOTE: Cannot be used with aluminum, redwood and/or close-grained woods like oak or cedar. For redwood, cedar, oak or other oily or close grained woods, Evercoat Everfix Epoxy (100642, 100643) will provide the best adhesion.
Do not use with Styrofoam.
Forgot to add this: If using Epoxy resin it also has a downside in that an amine blush, which feels "waxy" on the cured epoxy, the waxy blush must be washed away with warm water before successive layers can be laminated! if you don't do this your layers will eventually peal like a loaf of sliced bread!!

Jester
 
#14 ·
OK Brian, here is my take on doing or recommending this type of repair. If your working on a car that has no value today or in the future and your only concerned about it lasting for a few months...go ahead, knock yourself out, plug the rust with fiberglass. If your working on a classic, say for example a 69 Mustang and the roof is rotted out...would you recommend filling the rust holes or repairing the rusted areas properly by replacing the rust with metal or maybe, depending on the amount of rust, the whole roof. In my opinion it's not a matter of "next bestest", it's a matter of bringing a classic back to it's original condition. If the owner doesn't have the knowledge or the equipment then I would suggest one of 2 options, either get the knowledge and the equipment or hire a person that can do the job properly. Too many a good, restorable vehicle, and we've all seen them, have been butchered to the point where a proper restoration isn't feasible anymore.

In my youth I made too many stupid mistakes with cars that today would be valuable, be damned if I'm going to pass on information to people remotely suggesting that fiberglass out of a can is an acceptable and respectable way to repair rust or restore a classic.

Just my thoughts.

Ray
 
#17 ·
I'm with you Ray, the value of the car has a lot to do with it, I did it to my 59 Rambler, not exactly kicking fenders with the 65 Shelby. And again, I am talking not about my opinion on what is right or wrong with another mans car, just as I am not going to tell him what color to paint it. We aren't talking about a particular car like a 69 Mustang, we are talking these repairs in general and no car is mentioned correct? I thought that is what this thread was about.

Because most every subject in auto repair is going to change from one end of the spectrum to the other in quality depending on each car and each owners expectations.

I merely tossed out there a way you could take care of SOME repairs on SOME cars. What car and what repair would require a more thoughtful discussion.

As I said, my Ramblers repair was literally a test bed, I don't do those sort of repairs either, but being it comes up here and other forums now and again I thought I would toss out maybe a "correct way to do it incorrectly". :D

My Ramblers been on the road driving it every day for almost two years now, the floor looks exactly as the day I did it, both top and bottom. It has met THIS cars owners expectations :D And I have to assume with the 290 million car owners in America I am not the only one. So there is a place for this type of repair, that is all I am saying.

There are some people who are going to cut corners, I feel it is better to tell them to do it correct incorrectly than to tell them nothing being they are going to do it anyway.

Brian
 
#18 ·
Adding fiberglass to metal is no different then laying fiberglass on top of a sheel of glass,,, it will peal right off... Can you make it stick to metal... Sure you can... But not for long... It WILL over time pop right off..That's the point I was trying to make here..
 
#19 ·
What is the body structure on a 63 Corvette made out of? That is why the epoxy is applied first, the fiberglass is then bonding to epoxy. I understand your point and agree it isn't the right way to do it, but there is a little bit of a gray area that has worked for me and my Rambler, figured I would toss it out there.

Brian
 
#24 ·
Yes Brian...I understand completely what your saying and that's why I said, "my opinion"....I've done it, anyone whose been in the trade for any length of time has done it....and I'm confident that we agree and it is dependent on the car and the expected life span of the repair ....there is another thread on this forum right now entitled "Evercoats: Fiber Tech, Everglass, Kitty Hair, Tiger Hair, Metal to Metal", it concerns a 1968 Mustang Coupe with rust holes in the roof and the OP was wondering which product is better...I didn't want to respond to the thread but this thread has prompted me to respond.

Maybe read the thread and let me know what your opinion would be for the OP....Very often they may read another thread and think that the "bestest" way is an acceptable way, no matter what kind of car they have. My response was in more of a form of a question, which was "why not repair it properly", and I suggested that if they where on a tight budget to save their money and do it properly over time.

Again, just my thoughts.

Ray
 
#27 ·
I haven't read that thread but that is where the decision is made on a particular car or project. We were talking about in general that's all my comments were, in general.

Brian
 
#26 ·
I was saying that the epoxy primer sticks to the metal and the fiberglass sticks to the epoxy primer, thus the fiberglass doesn't fall off, that is what I had said and didn't understand your post that's all, geeeez Mr Grumpy.

Brian
 
#32 ·
I'm with you Ray, I feel the same way. I also don't believe in reproduction parts and refuse to use them unless it is the absolute last resort. But, I don't own every car in America, so to fit the owners of those cars I will do my best in aiding them. That's just how I see it. I will give advice to not do something if I feel it isn't the right way to do it, I offer the suggestion to not do it simply as advice. It's like this, depending on the car heck yes I will say DON'T DO THAT if some guy wanted to use this method on a car that should have it done right, but in just discussing methods of repair, I will toss this out there.

Brian
 
#39 ·
Newinteriors:
I saw your journal when I first Joined Great work! I build wood molds, Plaster molds, Chicken wire cardboard and duct tape molds, Etc LOL Even take new fenders release agent lay glass on em with wood bracing pull it of and use that as a mold :thumbup: Carved Styrofoam and layed the glass to form custom items!

Before doing floors all holes are opened up and cleaned of rust big rust holes are patched with metal and welded, sanded to bear metal bellow and above, duct tape (the resin doesn't stick to the tape) the bottom of the floor so no resin drips or runs out, I epoxy the floor scuff and lay glass before the epoxy is no longer chemically active! I found out the resin bonds better with the epoxy or epoxy sealer while the sealer is still chemically active but dry to the touch! If the epoxy is hard the resin doesn't bond as well even if you sand it!! If it says to paint the epoxy within 72 hrs then lay the glass in the same time frame LOL! You can hit the floor with a 10# sledge and it wont damage the bond. This type of repair is quick and Ive done it for some customers because fabing the floor or cutting out all the bad metal and welding in new was cost restrictive! I did a metropolitan about 12 years ago and its just like it was when it left my shop to this day But it sees no bad weather and the metal can rust away and the glass floor will still be there! You cant just lay glass on the floor and expect a good bond:nono:

I don't know how well rust killer coatings work to stop rust I've never tried those products or have I seen any one epoxy over them!

Glassing a floor, Not the best way but another way LOL

Jester
 
#45 ·
QUOTE
People can make it stick to metal.. BUT... Like I said,, On a fool.. I'm 240 and if you step on that floor just right... It will pop off the metal... Plus for some reason.. I have seen where people covered rust holes and it rust even more... Maybe the resin does something to the metal...Don't know...


"I played with glass a little.. Building this car with no mold...Here's some fenders I hand made as well..made a buck,then made a mold.then made the fenders,,,More on that in my journal.."END QUOTE


Fabulous work Randy...pure talent, and proper use of fiberglass in the true definition of use of fiberglass. That has to be some of the best work I think I've seen. For anyone following this thread take note, this is what and how fiberglass should be used.

And M5StudeGuy, I would very much like to say that you don't have anything to worry about but as New Interiors said...I wouldn't have done it like that either, it's not the proper repair or use of the product. You may be fortunate and not have a problem for quite some time (and I sincerely hope that is the case). A lot depends on how thick and (as mentioned) how much resin you used...is it a daily driver? Where you live and temperature changes will effect the life of the repair as well. If you live in a climate where you have drastic changes in temperature the expansion and contraction differences between the metal and the fiberglass will eventually cause the fiberglass to let go. The fact that you put a coat of Epoxy primer on prior to the fiberglass will help, it'll act like a cushion for the inevitable differences in expansion and contraction. This, although different, is similar to cars that came from the factory with lacquer paint...in cold then warm climates, the lacquer paint was prone to cracking more readily than in a more stable climate.

I do have a question, where did you hear that this was a proper way of repairing your roof? The reason I ask is because I'm very cautious when I give advice on this forum for reasons just like this.

I wish you only the best.

Ray
 
#48 · (Edited)
At this stage of the game your best bet is to not worry about it and enjoy your truck. Perhaps, looking on the bright side, if it does crack in the future, you can repair it then and you will know what not to do. I realize that it's a small consolation.

Currently I'm turning a Model A Ford 4 door into a 1/4 truck. The back section of the 4 door car was turned into the back of the cab. It was a lot of shrinking, stretching, hammer and dolly work but when it was done, a minimal amount of filler was used. All I'm really trying to say is that the extra work put into getting the sheet metal in the shape it needs to be pays off dividends when it comes to the longevity of the vehicle, not to mention the peace of mind knowing what's underneath that shiny paint.

I asked you who gave you the advice on how to straighten out the roof of your truck. The reason I asked was because quite often advice is given and sometimes it's incorrect. There's nothing wrong with questioning any ones advice or getting a second opinion. A rule of thumb if you question someones advice and you have any concerns and they say "don't worry, I've done it hundreds of times and never had a problem", get a second opinion, it's difficult enough to get through 20 jobs, doing things correctly with the same procedure and products and not have problems.

In the auto body world, there are painters and there are applicators, the painter is the person that cares about every job they do and takes pride in workmanship and if a problem arises, often has the knowledge and the ingenuity to fix the problem in the paint booth. There are body guys and then there are technicians, the technician understands how metal reacts with respect to impact (collision), heat (welding), fabrication (putting metal into the shape required for a repair or custom application) and has an understanding of current products and how they should be used. A body guy gets it close and carves the shape of the vehicle with the filler of choice. Just so you understand, there is nothing wrong with filler when used properly within the tolerances set out by the manufacturer.

I wish you only the best with your vehicle.

Ray
 
#49 ·
Murphy's Law ("If anything can go wrong, it will"):drunk:

I really believe in it!!!, If there is a moth in my booth and I lose it and don't kill it, When I run my last pass and shut the lights! It will be right in the center of the hood in the morning LOL! If I have a doubt I don't do it! As I get older I've seen Murphy come into play through out my life! If I Use a new product that isn't supposed to shrink there's Murphy LOL it shrinks! Pick up my coffee cup and Murphy makes the handle come off and it spills into my freshly mixed paint cup!:drunk: Primed a car then used Sikkens white sealer and the
filler color bleeds through the primer and the sealer! Sikkens says it cant happen Barry said its rare but then I get on here and guys that use Sikkens exclusively (all the time) say " Everyone knows you have to shoot a good sealer before shooting Sikkens sealer" :confused: :pain::drunk::eek: In all my years Ive never heard of having to shoot sealer before shooting sealer:confused: But then there's Murphy :evil:! I yelled at my son when he was about 5 "Get out of that tree before you break your neck:pain:" Murphy pushed him out of the tree and broke his arm:eek:

Now I'm old and look for Murphy every where! If I see anything that might happen I alleviate the situation because I know it will happen!


I think all of us have met Murphy at one time or another LOL:p

It just seams like if your working Glass He's Right there watching for his chance!!!!!!:evil: You mix a cup of resin cold your in the middle of applying a layer and the temp goes up 20* in in 3 min.:pain::eek: and your brush comes out of the cup and your resin is jelled:pain: :eek: Your glass is layed out smooth and well coated and rolled (no bubbles) You come back and lo and behold there's a wrinkle with air under it :drunk::confused::eek::pain: :sweat: LOL

Jester
 
#50 ·
Everything you just said is so true...even when you do your best to do everything the way it's supposed to be done. That's why I always get a kick out of guys that say "I've done it X amount of times and never had a problem"....I wish I was that lucky....anybody that says they've never had a problem either hasn't been in the trade long enough or is outright lying.

Ray
 
#53 ·
Very true. :thumbup: And just how screwed up can you do something that won't get out the door? I mean, "It didn't explode when I did it so it works". :D

Brian
 
#52 ·
I love your comment about the moth in the booth...one time I remember hunting down that same moth, it was a beautiful colored creature...so I cornered it, stepped on it and went back to clearing the vehicle and be damned if not 5 minutes after I was done I looked at the car and that SOB was doing the backstroke on the hood...LOL

Ray
 
#54 ·
Did a Model 'A' Riddler car years ago on my last Coat of clear a Crane fly landed right in the center of the cowl vent spread eagle just perfect The owner liked it and stopped me from picking it out!!!! so I cleared it for posterity LOL It really looks cool (like we planed it):p It didn't win Riddler though it came in about 5th probably because of the "FLY" LOL:mad:

Jester:thumbup:
 
#55 ·
And isn't it always the job that has to go by 5 o'clock, or the one that you take all the special care in cleaning, blowing down, tacking and making sure your booth could be on the cover of Good Housekeeping and what happens, for some unknown reason you get everything from dirt and fly's to small barnyard animals in your paint, (bit of an exaggeration....I'm pretty sure the baby goat stuck to the roof was planted there by one of the guys in the shop...LOL...no hoof prints on the hood or deck lid).

Ray
 
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