Glue on flares: Who has done this and what have been your results??
 

I am considering using an adhesive bonding material instead of welding the flares onto my car. What are the advantages/disadvantages of doing this? Also, have you noticed any cracking where you have to use filler?

Thanks guys,
MIke

Adhesive is best used for fiberglass. Metal flares should be welded.

There have been debates and discussions on this several times before. As a result, I went to my b-in-law who is the auto bodyman in the family after his father, (my wife's dad). We've seen a lot of bondo dust in this family. Actually, the old man started with lead after he was discharged from the service (WWII).

Getting back OT, b-in-law has used the bonding process extensively as it is called for in many reconstructions as a factory process on some makes. I can tell you that from his experience, it won't fail if you have clean, well prep'd parts. Depending on which way the seam goes, up or down, water might get in between. That will never haapen with a butt weld.

However, as a carpenter, I never install any wood siding where water would run but down and away. You would do the same with your fenders. All it takes is a one inch overlap and there is a tool for rolling the offset flange.. He has done it, I have not. I can tell you that stitching in a fender flare takes some time even after all the fitting is done. Once you get the fit and some temporary locaters, bonding is quick and efficient.

Not anymore. Now, using advanced adhesives is actually the preferred "factory" way to do many auto body repairs. Take a look in a new Porsche workshop manual. It's all about tubes of catalyzed adhesives...

Yeah, IF YOU have the tools. A very good friend of mine does, he spent close to 80K on tools to be certified to fix the JUST aluminum bodied Jags....

I doubt the original poster or the average Joe has the coin for that....so, I stick with my original opinion.....

I had to install some flares on a 914. I thought about gluing them on. I found the adh. is very expensive and I would have needed to flange the fender and I didn't have that tool. So I ended up butt welding the flares

I had my flares bonded on 7 years ago and I have had no problems at all. I personally think it is the way to go because you avoid any potential issues with a crappy welding job, plus you don't have to worry about corrosion along the weld seam (seen that alot).

Mike

FYI, the adhesive is called 3M Automix Panel Bonding Adhesive 08115.

this subject came up a little while ago.. and the 3M glue goodies site was posted. many fender glue options.

Many manufactures use this method because the panel alloys are increasingly difficult to weld without warping or becoming brittle. My question would be "is this panel important to structural integrity?"

It seems it would be more important on a 911 than on a full frame car.
However, some have great results.........

The show Two Guys Garage did a piece on bonding a 1/4 panel onto an El Camino (?)...it was pretty informative.

As always, be sure to prep the metal surfaces properly before applying the adhesive. Any contamination of the hydrocarbon or silicone variety will compromise the bond.

I do not have experience with metal flares, but I did successfully bond fiberglass flares to my fenders. I used glass matte and resin over the joint before applying filler in order to strengthen the bonding area and to resist cracking from vibration.

Lastly, if I was putting flares on a race car, I would use dzus fasteners. If you mangle one you can remove it and replace easily. Once you bond and fill, it will be more difficult to replace than it was to install the first time.

Mike, I don't want to seem like I'm always bustin' your chops, but the only tool you would need here beyond what you would need for the welding is a flange roller. Eastwood sells one that is, of course, overpriced. But even at that, it isn't that expensive. The one my b-in-law uses is real nice. Zips right around the cut out opneing. It does cost $100 though.

The key to your statement is "certified." My b-in-law is certified to weld on collisions as are all bodymen today that work on unibody cars in approved shops. It's a state (fed?) requirement according to him.

Flares are not structural, so it's not a critical thing. We just don't want problems down the road. Mike, you, I and others have to start accepting that the new stuff works.

One last point that was not made above, it you butt weld, you have to go slow and weld an inch at a time and move to another area. Ohterwise, you will get serious warpage. You can hammer the welds flat if you can set down the welder and pick up the hammer and dolly fast enough. And if you leave one pin hole, it will rust through eventually.

Well, opinions differ...so be it.

I don't mind chop busting...you just have to stand in line with the wife and kids...

I guess my concern, and I know I will get disagreement here, is if it is structurally important. A fender ususally isn't so adhesive is fine. Rockers, IMO, are, so I would weld. As adhesives improve that issue will disappear. One last issue is authenticity. If it is important to you, do what the factory did. If not don't worry about it. I know a couple of guys who spent the $ on having their 356s leaded instead of polyester filler.

Modern epoxy bonds as used in this type of installation are every bit as strong as welded an suffer none of the negatives, such as warping, heat embrittlement and corrosion suseptibility.

Great info guys. Thanks for all the response. It seems like there are only advantages to using the bonding adhesive instead of welding.

One more question, when you use the flange tool, does it allow the panels to watch up like a butt weld would be? Do the two pieces of metal match up on the same level??

Mike

Yes, that's what the tool does for you. There is an over lap of one inch or more. One has to be on top of the other. What the flange tool does is make a step. So, the edge of the non flanged piece is level with the other piece while on top of the flange. It is level with the other piece on the top side only. Is that what you mean?

I attended a seminar on this body repair technique about 2 years ago. I was surprised to find that the factory fenders on so many cars are now bonded not welded The Oldsmobile Aurora is one example that was mentioned. The recuring problem the body techs were having the most discussion about was the visable seam that would appear after painting . There is a concern that the adhesives are softer than steel and as a result are easier to undercut when blending in to the base metal.Others thought it had to do with swelling caused by solvents in the top coats of paint. These are a different set of problems than could be experienced with the more conventional welding methods.My best advise would be to follow the adhesive companies recommendations to the letter and buy your paint from the same supplier so they can,t blame each other if a problem develops.

Thanks again.. Zeke, that was what I was talking about, thanks for that. I am a general contractor too, I noticed you do that kind of work in another post (i think). What types of work do you do?? I work with just one other guy (my boss) as I am only 22 but looking to start my own business here pretty soon. We mainly build additions and remodel kitchens/bathrooms. I would like to get into trim carpentry though. Kind of random, but just thought I would ask/mention that.

Mike