I just got a copy of this GM bulletin out the this months ASE news letter. The idea of gluing in patch panels, floors, etc come up now and then and I thought I would give you another perspective. If GM thinks it's ok, it must not be "that" bad right? First thing I would like to say is that the "big boys" at GM, Ford, Honda, etc have been pretty adamant about using adhesives, with a big NO. "If we welded it, YOU weld it" is their response to the idea. So I find this interesting, they have layed out how to "glue" this patch in where it was welded before. I think anyone who has studied and/or used modern panel adhesives will agree, they are as strong or stronger than welding. So, that is out of the way. The only real issue has been if you were to use it where the seam would be seen you would have a "sight line" after the different componants (metal and adhesive) expaned and contracted at different rates. It wouldn't fail or anything like that, you would simply have a very faint but real line where this seam was made. Now, I feel that even with that, there are some places where gluing in patch panels is the right thing to do, even with the "sight line" problem. Not every single car needs the perfection of a hammer welded, metal finished repair. Gluing in a patch low on the panel would likely produce a repair that is adequate on most of our cars. In many cases like on rust repair similar to this bulletin on the rear of a '68 Camaro it makes perfect sense if you are not a skilled welder or lack equipment. You wouldn't want the spice to be so far up on the top of the roof, you would want it back at the edge but you get the idea. Just a thought, there is a place for adhesives. graemlins/thumbsup.gif

http://members.aol.com/whatcouldiknow/gluepatchpanel.jpg

Martin, excellent post!!

Panel bonding has a place in the auto repair business. Ive seen its strenghs proved many times, both on destruction tests and out in the real world. You mention patch panels and my fav application of those panels would be cab corners. Chevys rust out like wild fire up here. Many times after repalcing a rusted cab corner its starting rust again in about two years. Now with the glue Ive yet to see any rust return on those corners since you arnt buring way the primer as you would with welding. I glue them at the top and down the back of cab and then weld them at the door jam. My top splice is under the mouldings so any "sight line" would be invisible. I love the stuff its made my life alittle easier :D ...Eric

Right on Eric, I have been thinking about a lot of things you could use it for. How about custom work? Sectioning a body, you could glue the panels back together in the middle with no warping. How replaceing the skin on a roof, glue it on, it is better than welding, no corrosion problems. I really think it is a super way to do things. You know, we fight and fight new methods. Looking at it like it is inferior to welding, it is NOT. It is another way to hold something together. An F117A Stealth fighter is all glued together. A Corvette has been glued together since the very first ones off the line in 1953.

I feel it is much better than welding in may applications. I just glued a roof panel on a 2002 Lexus LS430. I migged it at each corner, spot welded it at each "pinch weld" across the top at the windshield and back glass and then "glued" it at on the sides from front to back. Welding this would have created all kinds of headaches. Gluing it was BETTER than welding it.

Martin, those roofs are a great panel to glue, its so much easier. About 5 years ago right when glue was coming out in my area, I built a 97 grand prix for my sister. Needed a right door, quarter and roof skin. I glued the skin down the sides and on the window channels, only welded the roof at the corners. She still has the car and Ive yet to see any type of "failure" with the glue graemlins/hurray.gif

Its funny you say we fight new methods. How many people fought base clear when it first hit? Now people are laughed at if they are using lacquer or even single stage. Soon base clear will join lacquer...can you say WATER borne...Eric

I just saw that bulletin also.Glue can be safely used on any part that is not structural.No need to take the chance on burnin up those interiors,especially on roofs!!I have glued in patches since the stuff came out and have yet to see a problem.As MartinSR said the only problem I have seen, besides techs not putting it on right is the line between the two panels(sail panel).On light colors you can get away with it but not on dark colors.
I have had flash burns 3 or 4 times and now my eyes are super sensitive,I try to stay away from welding and just paint :D

ive used glue and havent had any problems i was told by a friend he had site line on his 1/4 panel i so i asked another friend he said if you flange on a long peice you will get read through he just over lapped his and didnt have any problem and i flanged mine and no problem with site lines i dont know if it was the way it was applied or not any advice

I have a question, if using glue is stronger than welding and less corrosion, why is it not recommended to glue in full floor board panels? It would be so much easier for a novice welder like me. I would think if i place glue on most of the surface area on the underside of the floor, it would hold tighter than random spot welds?

Frank

Frank just beat me to the very question I was going to ask...I have to replace floors in a 67 Camaro very shortly, can these be glued in? I have to start looking into this gluing thing as an option to welding, I can weld OK I suppose, but I dont like doing it. Can someone comment on the floors? And where would there be more info on this process, besides GM bulletins. Thanks, John

I believe floors are considered structural and should be welded in solid.I have seen bodymen partially glue in trunk floors though.If your welding is not that good I think gluing would be stronger? MartinSR?? I have seen cars that had glued on 1/4's been rear ended and the glue held very well (if applied correctly).As bad as my welding is I would ride in a car I glued floors in!!!
Get more info at your paint supply store,they might have videos also. Mike

"If your welding is not that good I think gluing would be stronger?" Very interesting observation Mike. I have to say, I have seen MANY "pro" bodymen that can't weld worth a crap. If I HAD to have these fools work on my car I would much rather have them glue the car together. I just had a car on the rack to do a wheel alignment on. The rear floor and frame rails had been replaced. This was a 2000 or so Honda Civic. I will tell you right NOW, it had about 1/4 the strength it did from the factory! :eek:

Now, this isn't to say that you should just glue things because you can't weld well, it means you MUST get better welding skills.

On a floor of a Chevelle I think you could glue it all in. I would have go out in my garage and look at my Skylark, but I believe the mounting bolts go through supports in the side rails. The floor is only there to "hold your carpet up". I THINK that is how it is. Now, even if there was some structural purpose to the floor, you could strategically weld here and there and glue the rest.

Which brings us to another point, the adhesive used incorrectly is just as bad as improper welding. If you look at my "Basics of Basics" on door skins I think I cover the use of adhesives pretty well.

Is glue stronger then welding?? It all depends how good you are at welding. Some tests Ive seen done to the glue is once the 3M rep stopped by to put on a little demo for their glue(#8115). He had two pieces of similiar metal each one contained two pieces of metal overlapping. One was glued the other was spot or plug welded. He then took the metal over to the frame machine and pulled each end apart. The welded piece broke at the welded joint, as were the glued piece started stretching the metal before breaking :eek: After seeing that I was a believer in the glue. But who is to say that he rigged the welded joint!? I dont think so cause Ive seen cars that we have fixed and later crashed again and the glued on panels still holding tight.

Am with Martin if you are at the point which you think you need to fully glue floors in cause of your poor welding skills you should raise those skills. But I too would have no problem riding in a car with glued floors, hell Ive riding in street rods that are nothing but fiberglass. I would weld the floors to the braces and at the rocker but glue the rest. Making a spot weld isnt that hard so I would weld that area...Eric

Hey sevt... the water bourne enamel was already tested by G.M.,Ford and Chrysler from the late 80's to early 90's and they all had MILLIONS of dolars in warranty repaints......I know cause I was one of those painters. I have a feeling though that there on the way back into the marketplace with all the V.O.C. regs that have been handed down over the years.

Note to self: take all the extra cash you have on hand right before this happens......buy Urathane clear by the case hold on t0o it for a while and sell it on e-bay by the gallon and become a millionaire graemlins/thumbsup.gif

Note to self: take all the extra cash you have on hand right before this happens......buy Urathane clear by the case hold on t0o it for a while and sell it on e-bay by the gallon and become a millionaire People tried that with R-12 refrigerant before the R134-A change over. I haven't heard of any millionares yet. ;)

MartinSR, just painted all the inner stuff on my buddies 71 GS today. I was asking him about the glue(he's a real bodyman) and since the older cars have frames, floor is not really structural so shouldn't be a problem.
I have seen bodymen put a little bead of glue on one of the panels and clamp together,this is not the way to use this stuff.
I have used this stuff for everything!! Fixing stripped holes in my console,clips didn't line up on my door panels so I glued them in the right place,fixing A arms on my RC cars.If used right this stuff is amazing!!
I too have been in the business 20+ years and have seen guys I wouldn't let put my wheelbarrow together!!! :D

Everybody I know wants 60.00 a can for that r-12.GEEEEEEZ for the 12.95 kit and a little extra in parts changovers I would rather do the 134-a changover
When PPG stopped producing the 2010 clear I bought up all I could,man that stuff was hard as nails when it dryed.The clear I've been using for a while now 2020 or whatever rock chips very easily

I have 19 years body experience, I have seen failures with the adhesives, 1 was the application---do not use plastic or epoxy encapsulated wire or abrasive wheels to remove the e-coating/primer. These wheels sometimes leave a transparent film not visable to the eye, if turned at higher speeds. If the film is not removed it acts as a barier and will not let the adhesive contact the metal surface. Sandblasting or #80 roloc discs work without failure. I once had a customer drive in with a Dodge pickup that had the roof almost completely torn off on the highway. The shop that performed the roof replacement used a fiber disc to remove the e-coat and didn't know about the transparent film it left behind. The other failures I've seen had to do with adhesives that had exceeded their shelf life. I prefer the Lord Fusor brand but have also used the 3M stuff with great success. Glue is great but only as good as the user. If used properly the bondline will not be visable on patchwork. Another great advantage is the ability to address corrosion protection before the patch is installed--simply prep the panel for the bond--apply masking tape to protect the bonding surfaces and then apply epoxy primer and rustproofing to the panels backside-then remove the maskingtape to expose the metal surfaces for bonding-apply your adhesive and install--don't try rustproofing a patch that will be welded or your car may burn up. I could go on and on. Bob

Very good stuff Bob. I always grind the area with a 24 grit disc just as the tech sheet says smile.gif

Excellent point on the fiber discs Bob! Now that you mention it I believe Ive even seen a 3M bullentin advising agaist the use of those fiber discs. Like mentioned before its all in the prep work that goes along with the application of the glue. Just with anything else... poor prep work poor end results. Thats why reading the instructions and knowing what you are doing is so key...Eric

ok, so say I am installing a partial quarter panel that has a flanged seam across the top, vertical behind the door, and at the rear bumper. If the quarter fits well, can it be glued and held in place with sheet metal screws until dry, and then finished off as normal with a skim of filler? Or should I plug weld the quarter every so often after the glue is dry? I would like to try this stuff but definately dont want any ghost lines coming back later after its the car is painted. If I should plug weld it, how far apart should they be? Is this finally the way to stop filler from bubbling out of repair seams years after a repair? Also, once you open a tube of this stuff do you have to use the whole thing or throw away whats left?

Dave, your talking about an "80 %" quarter? It sounds like it. If that is true than gluing wouldn't be advisable. The reason I posted this to begin with was to show that there are uses for adhesives. Even ones that we had previously counted out. Yours is one that has definetly been counted out. HOWEVER, if and that is a big IF, you find yourself with no means of welding and you just can't afford to pay someone to weld it in, yes, it is at the very least an option. It is like building a motor with a used cam or lifters, yes it can be done.

You would be asking a LOT of that glue. It would hold it alright, that isn't an issue. But the "sight line" that we have been talking about would be a HUGE issue. It is very likely that you would see exactly where the seam is after the car is painted. It may be faint, it may be darn near invisible unless you know where to look. Or it may stand out like a darn pin stripe! The procedure and or the products used could make a big difference in the out come. I personally have never done anything even close to that. Hopefully one of the guys with more experiance on the subject will give you some ideas on how to or whether to do this.

I have seen this tried countless times and have always been able to see a line in dark colors,guys I know always weld the sail panel.
We always bake our cars after painting so maybe that has something to do with it?

Martin,
no problem welding one on, thats how I have been doing it. Just figured it might be quicker than all the stitch welding needed to weld one in. I havent had any problems with bondo coming out of my welded seams, but I have bought cars that had the normal patches (lower fenders, lower quarter areas) that looked good but only for a few years if the car wasnt kept in a garage. Maybe butt welding is the only way to go with lower patches, the flange welding doesnt seem to hold up down low but seems ok for upper areas.

flanged or lapped seams are very difficult to protect from oxidation, no matter if seamsealer,primer,rustproofing is applied there always seams to be an open spot that starts to rust. Weldable primers are a great idea in theory but do not work very well proven by my own personal salt water testing. The bottom line is if you can protect the metal from contact with oxygen it will not corrode. If you submerge a piece of steel in a bath of oil it will last forever. The best seam to use in sheetmetal welding to address corrosion is a butt weld or flush fit-this enables you to protect the surfaces entirely unlike the surfaces within a lapped seam. Adhesives require a lapped seam for installation but the adhesive also acts as corrosion protection within the seam. Undetectable patchwork can be done if careful attention to detail. The panel must fit perfect and the seam must be 1/8" below contour, the overlap should be at least 1" wide, hammer and dolly work is required, do not use a panel flange tool they distort to bad and only provide a 1/2to3/4" lap, test fit the patch and make adjustments untill the fit is perfect with the seam 1/8" below contour, temporarily secure the patch with sheet metal screws 3" apart and check the fit again, when the fit is correct remove the patch and drill the holes in the patch one size larger, gring the edges of the patch at a15degree angle untill the very edge is paper thin, grind clean your mating surfaces thoroughly and apply the adhesive per instructions, attach with the sheet metal screws with the appropriate pressure-do not squeeze out all of the adhesive, allow to dry overnight preferrably, remove the screw and countersink slightly with an appropriate drill bit, grind clean off all of the excess adhesive, apply 2-3 coats of premium epoxy primer and let fully cure, finish the repair area with evercoat everglass or marson's marglass followed by regular plastic fillers, apply 2 coats of epoxy primer followed by fillerprimer for sanding-----this has worked without failure for me and is undetectable even on perfect black finishes and I mean perfect-as in Dupont top gun award perfect. As far as welding goes I do know a way of doing a lap install that will hold up indefinately but the chances of burning your car down during installation without the proper preventive measures is very very great-and I don't want that to happen to anybody. The old hammerwelding technique is still the best but can only be done on areas with good access to the backside. Bob

Thanks Baddbob, I have some patches to do on 2 MG's and will give it a try.
Just to clarify,I should make the patch and leave 1/8" lower than the good metal and fill with Duraglass? Fill screwholes with glue,after it sets up? Thanks Mike

drptop, 3M stats right on the intrusctions that all welding should remain at least 2 or more inches away from the glue. The heat will burn away the glue, leaving your panel only held on with the random spot welds. If you plan on gluing the top seem on that 80% quarter you will have a "sight line". Right when the stuff came out I did quarter replacements on a 68 Buick Skylark. Welded the door jam and around the taillight area and then glued the top seem. Not til later when the car was painted(dark blue) could you see the line. Didnt see it while blocking primer or painting saw it after it was done and on the road. My guess is that when it finally meet some temp changes the metal and glue expanded at diff rates, causing the line. Havent seen the car in almost 5 years but at the time the line was very faint, kinda looked like 20lb fishing line run down the quarter then cleared. Of course you could hide the line by running a pin stripe down the side of car tongue.gif

Also dont fill the holes shut with the glue, same thing will happen-ghost lines! The best thing Ive found to do is what baddbod mentioned, coat it with some expoy then bondo over that, just besure you coat the backside also...Eric

Eric, go back and read Bob's post. Pay particular attention to the part about beveling the edge. Then go back to the GM bulletin I started this thread with, they say to do the same thing. I have to believe Bob in his testimony that this worked for him. This seems to be the difference between success and failure. I know I have never done that, never would have thought to do it being the metal is so thin. But if you'd do it with fiberglass, why not metal? Hmm. smile.gif You didn't mention that you did this when you had your "ghost line", I think it may be the answer.

I too have never done this, I just have to wonder with the bulletin and Bobs testimony if this is something that could be a viable alternative, not just an alternative, we know it is, but a real dare I say "equal" alternative. Just wondering smile.gif

Bob,
good info, but what do you fill the sheetmetal holes with after removing the screws and countersinking the holes? Do you fill them with adhesive also? Or with the everglass? Also, how do you get a distortion free full 1" flange without using a tool to do it? Again, once you open a tube of this stuff is the left over savable or do you have to use the whole tube? Maybe I will try this stuff with a lower fender patch first, if I get a ghost line I can always grind it out and weld it later on. I definately dont want to be redoing quarter panels. smile.gif

Thanks for the responses, I like the idea of spot welding by the rocker panel and using glue for all the rest. This will save me time, now i can get her back on the road in april!! :D

Dave, the adhesive in the mixing tube hardens and you just leave it. The next time you use it you just change to a new mixing tube and off you go. smile.gif

Too late, I've already bought a MIG welder! graemlins/hurray.gif

Randy, I have a MIG at home. We have three at work along with a PRO SPOT strsw and that doesn't stop me from gluing. There is a place for both.

I don't understand why you would see a ghost line? :confused: If you over lapped the seam and cleaned out the edge where the glue comes out and then filled it over with plastic filler then how do you get the line???Does the glue bleed thru?Or does it shrink over time pulling on the filler? Man,I was thinking this would be a great way to put on a skin 1/4.
I'v used the glue to put my nos 1/4's on my Elky but only along the lower edges then tacked the top.

Rick

Martin, the bevelled edge might be the trick I dont know!?? Like I said I did the car around 5 years ago, and everytime something new comes out we fully dont understand til later. :( I know I did the lap with the patch below the original metal but as far as the bevelled edge I dont think so. It would make for a great experiment to test this idea or theory. Not second guessing anyones idea just know what happened to me. If GM says it should be bevelled it should be done that way cause they spent more time and millions of bucks testing this stuff in high tech labs. Am just speaking from what I have experienced in the shop the same as you are smile.gif

I would love to hear more about this. Martin am sure its hard to see the cars after they leave your shop and keep tabs on them but I would like to know if this bevelled edge is the trick. I would like to compare notes sometime after doing a few more of these repairs. Am game if you are are graemlins/beers.gif

Yeah Eric, It is something that I really don't know. It sure sounds interesting, and it makes sense. I have been actually thinking about where I can test this. I can't come up with anything, I'll have to wait for something to come around. I can't do it at work being my boss wouldn't want to "experiment" on a customers car.
I don't follow GM in a jack boot step but like you I have to believe they have done their homework on this. I mean, this bulletin is for repairing one of their screw ups :rolleyes:

I just started at a new shop or I would try this,take an old hood or fender cut it in half and glue it back together. Maybe beveling half of it and just overlapping the other half?A little bondo, prime and shoot some black on it.
I too would really like to know if that's the ticket. Mike

I found a web site that sells dura-mix and lord fusor products, they sell the adhesive along with the gun. Has anyone used this LORD fusor before? this company seems to say they sell more of this than dura-mix. i dont know if this helps much, just trying to contribute a little because ive learned so much from this site, especially from SR martin knows alot!! and from sevt_chevelle, along with everyone else who contributes.

http://www.crestnetsales.com/index.html

Frank

My nephew is an engineer with Lord Fusor [works on the adhesives for composites] and sent me this link: http://www.fusor.com/products/all_products.asp
He says that all complaints of "failure" or even dissatisfaction when using the products have been traced to some deviation from proper procedures. The most common problem is apparently pulling the panels apart to adjust fit rather than sliding them. Once the panels are pressed together, any air introduced will prevent proper cure. BTW their instructions also state that the edges be beveled.