Hit it with the mig,and cool it with your air hose to keep the heat down,If you decide to use a filler,use a waterproof filler so moisture can not come through the holes from the backside and bubble the paint,Darryl

 

I am sorry, I disagree. If you weld that hole with ANY kind of penatration the adhesive within a half inch of it is TOAST. Heat is "Kripton" to these adhesives.

If you are trying to bond a line that is then going to be seen like a seam from quarter to roof, I say you should be welding it anyway.

Why would you need to cover up the bonded seam, it is usually used on a pinch weld or something like that where it will not need screws.

Brian

 

i agree do not weld near the panels that were glued, this is the way that they remove the glued panels heating to 400 degrees breaks the bond, at least with the norton adhesive.

 

Whats the difference between mig welding and spot welding that some shops do to a seam they have glued if you cool it down quick?personally its worked for me as Im from the old school and add the welds (not many) because I feel the jury is still out on panel adhesion,Darryl

 

I think panel bonding is something that was greeted with skeptisism (and for good reason) but has proven itself. If I'm not mistaken many of the glues have a higher tensile strength than the base metal. It's also used on new cars by the factory.

Several advantages, IMO. I like the idea of being able to paint the backside of something, and not burn it off by welding.

 

Im a little new to this site but have been doing body work for a long time. I have not ever bonded any metal pnls. only fiberglass on Corvettes. This is the second post I have read on bonding steel pnls. If you want a quality repair, DO NOT BOND IT. I guess the first time I ever put a patch in I pop rivited it. Oh ya, their was the one time I backed the hole with cardboard and skimed over it with bondo too. but thease were NOT quality repairs. It takes a little more time to repair by welding in metal but it is by far the best way. SORRY for the info but U will thank me 20 years from now.

 

I used the 3M panel bonding adhesive on the wheel well to quarter lip and the quarter to to trunk gasket area. Vise grips and clamps to hold tight. Everywere else I used screws and vise grips to hold it tight then plug welded. I'm new to useing the adhesive but I like the idea of no moisture or rust in the areas I glued.

 

I see. I used body calk on my quarters and plug welded them no prob.

 

I guess the first time I ever put a patch in I pop rivited it. Oh ya, their was the one time I backed the hole with cardboard and skimed over it with bondo too. but thease were NOT quality repairs.

I've never bonded a panel either (nor am I a pro). That doesn't mean I think welding is the only solution, just that it was the best solution for a long time.

I can tell you from an engineering standpoint that your comparison to high-school jalopy techniques isn't really all that fair. These are pretty high-tech adhesives. They will not cause galvanic corrosion (pop rivets) or absorb water, crack and rattle out (bondo over cardboard).

The nature of this site is that we all appreciate old-school techniques, and the higher level of craftsmanship that it took to properly use them but we should also keep an open mind to technological advances, especially those that make the hobby more accessible to those without a welder and the skill to properly use it.

JMO

 

My question is how the glue will hold up over time. Cars are made to be replaced at some point, so the glues performance after 20 or 30 years is irrelivent to the manufactures. I wouldn't want my quarters to fall off 20 years from now becasue the glue didn't hold up.

My second issue is that these cars were designed to be welded, so why not weld them. Newer cars are going to the glue method so you don't want to weld them. Plus it's hard to weld tinfoil

Glue has it's place and it's not on my car...

I guess it shows that my knuckles drag the ground from time to time eh?

David

 

Whats the difference between mig welding and spot welding that some shops do to a seam they have glued if you cool it down quick?personally its worked for me as Im from the old school and add the welds (not many) because I feel the jury is still out on panel adhesion,Darryl

The difference is that MIG welding has a much larger heat affected zone than resistance spot welding does, regardless of any methods to cool it after the weld. With Squeeze Type Resistance Spot Welding(STRSW) a smaller area will be burned away right at the weld area.
I have used STRSW to weld two 18 gauge coupons together with a platic soda bottle between them. I put a few ounces of water in the bottle, placed a coupon on each side, clamped and welded. After the weld NONE of the water would come out even though the weld had gone thru 2 sides of the bottle. Upon disecting it I could see a small area of the bottle had melted and resealed to the steel. The panel bond works this way when weld bonding.

Among professionals who have properly used the products and studied the
performance data, the jury is not still out, they/we use panel bond.

I only use it in areas where I can fully clamp with vise grips, I normally weld the other areas. I did however put a partial 1/4 on my drag car with only adhesive by wedging some 2x4's from the shop wall to the upper 1/4 seam to hold it in place. (over 9 yrs, still looks prefect). If you read the 3M instructions, there are guidelines on where you must weld instead of bonding.

If you turn the air way down on a pneumatic punch tool, you can get a mark in the 1/4 that looks like a factory spot weld, then you can glue the panel on, try that with a MIG.
The ability to completely seal the lower areas of the car with the panel bond is very appealing to me. Some of the crash test data is also impressive, there are some concerns the car can become too strong for late models.

 

I agree cobra, I want to see actual results proven not by data but by time for restoration sake, and to techdata I am also a professional, but on the restoration end of the trade,I am still on the fence on the panel adhesive and have read up on it,the debate on this thread proves the jury is still out,have you ever heard the term, dont believe everthing you read(data).cheers

 

True, I wouldn't believe everything I read.
I had a coworker spend a week plus with an independent research firm.
We were looking at a few applications of bonding for a few new products.
They did accelerated tests in environmental chambers (for more than the weeK) and a number of other tests including crash testing vehicles, I could never get him to let me tag along when they did the crash testing, it wasn't part of my job. The environmental chambers do a surprisingly good job of simulating the affects of weather over a given time period.
Long term durabilty was a concern, not just 5-7 years that a car is expected to last.They also did endurance testing over a washboard type surface, loaded and unloaded. The lab and field testing backed up what the various manufacturers had claimed in their data. The corrosion resistance was extremely impressive.
I feel very confident in the products based on what I have discussed with the engineer who set up the tests.
I can understand some being skeptics, I just feel I have seen enough to trust it on my car and customer's cars. If you don't feel the same, then don't use it welding has worked for many years and is still a great method.

 

I, also, don't believe everything I read on the internet.

We use similiar products to build antennas.
Not little antennas, big cell-tower antennas.

I personally am in charge of prototype fabrication and qualification. I have an enviromental chamber as well as salt-spray and vibration systems. We use MIL-spec testing methods to simulate years of operation, miles of operation, etc. I do this kind of accelerated life-testing ALL THE TIME! I also perform tensile testing, shear testing, water immersion testing, impact and drop testing, etc.

Keep in mind that on an antenna the adhesive is all on it's own, it isn't protected by epoxy primer, topcoat, etc, it's totally exposed. UV is the biggest killer of any plastic. On a quarter panel it's protected since it's underneath.

Now, I haven't tested actual body-bonding products, but we commonly use all manner of high-strength urethanes, acryllic adhesives, many many kinds of rtv, silcones, etc. Please don't jump on me for not testing Fusor's products, although if someone sent me a sample or something I would do it.

Anyways, we have antennas at both the north and south poles that are 30+ years old. We have antennas on the top of multi-hundred feet towers just as old, some older. We make air traffic control antennas, naval military antennas, and have sent antennas into space. You get the idea.The point I am making is my companies products are more critical and sees worse environments than our cars do. If an Air Traffic Control antenna fails, that's BAD! And the cost of installing a replacement cell-tower antenna DWARFS the not inconsiderable cost of the antenna itself. We cannot afford to have are products fail, we must super-overdesign them and constantly refine them if something comes up. Our company has a heritage of building THE most durable antennas in the industry. That is not hype, it's how we justify our prices . But it's true, also.

We have been using adhesives for 40-50 years. We occasionally update to newer formulations if there is a reason to, but the point is this:

I understand that it feels cludgy and half-assed to even consider gluing quarter panels on your classic chevy - I really do! I feel it myself. "if it aint broke don't fix it", I'm not building a plastic car, etc. Well, the reality is that welding panels definately works, but has disadvantages in a bodywork setting. Warping, burning off paint from the backside, labour-intensive grinding, we have all experienced these at some point. A skilled welder is better at avoiding this pitfalls, but it's still a concern.

Scientifically speaking, the "jury is not still out", adhesives are a proven technology. Keep in mind, this isn't "Krazy Glue" or Elmers white glue, etc, it is super-high-tech stuff. The jury is only out on whether the average person will feel comfortable using them. But those who have to work with the stuff on a daily basis know how strong the stuff is.

I have several adhesives at my disposal just for building prototypes, and I'll say it again, if the surface is prepared correctly the adhesive is stronger than many base materials you put them on. If you bond quarters onto your Chevelle chances are the adhesive will outlast the car. They do come with a lifetime guarantee (yes, I know, a guarantee is no stinkin' good if the panels fall off, the damage is done). At least they are confident enough in their product to put the guarantee on it.

Tech Nova points out a potential problem...that modern cars are designed to absorb impact by crumpling, and adhesives can potentially make the car so strong it doesn't buckle any more. Classic cars rely more on brute material strength rather than crumple zones, so it doesn't apply quite the same.

I understand the reluctance to deviate from the tried and true and I understand why the average person off the street might question the longevity but the stuff is tested. Adhesives are worth considering, IMO. You make elect not to use it, and maybe I will too (for now). But it's not snake-oil, the technology is there and proven.

My $.02

Now I'd better get the heck back to work!

 

Technova, Dan, I am copying both your responses to save. If anyone can read your very elequent, responses and still say "glue is hack", they just don't wnat to ever learn.

Like I have said before, you will get in a "glued", blown hydro and go across the lake at 80mph, you will get in a "glued" plane and go 500 mph, but you can't phathom gluing a quarter panel in a few places on your cruiser 68 Skylark?

They ONLY reason cars are welded together these days is it is CHEAPER, PERIOD. If it was cheaper to glue, they would design the cars around it, PERIOD. And they are on many componants, including frame members and body side inclosures on some high end luxury cars.

There is a place for it, many places for it on vintage cars.

Brian

 

OK I have been doing body work for a long time. the thread started when you asked if it was ok to weld some part of the pnl didn't it? WHY did you want to weld any of it? Why are you asking the experts for advice in the first place?
My first guess is that you care to do a restoration of your 30 year old car. Otherwese you would let it rust out and buy a new one. That being said, I thought I would ask why you want to bond it.
when you do "restoration work" you restore the car to "origanal condition" yes you may choose different paint, drive train ect... BUT the body was made one way. welded and pnls fastened by bolts. I don't care what metal fab guy you ask, if you ask the proper way to repaire a steel car pnl. that has a rust spot, they will tell you to replace the patch by using steel patch welded into place. PERIOD. I can see in twenty years, you will never learn.. Hey, if you dont like what I said then don't ask....

 

I'm walking away now...


:sad:

 

Brian.

Lets just assume a mig spot weld will melt a half inch of panel bond, I'm not trying to quote you on any specific numbers here.

So what I have here is assumptions only.

A spot weld cutter is 13/32 or .406 thousands of an inch

Spot welds vary from 1 1/2 inches to a little over 2 inches between them.

So lets say it's 1 3/4 inches between spot welds = 1.750 thousands of an inch

A #10 type ab sheet metal screw is 9/64 or .140 thousands of an inch body dia. The thread diameter is 3/16 of an inch or .187 thousands of an inch

So lets say the mig weld will be .187

The factory weld is .406

If you put sheet metal screws every three inches with panel bond in between' pulled the screws and mig welded the holes shut, you have.

Factory weld .203 on the inside of the two factory welds, minus 1.750 = 1.344 or 1 3/8 inches with nothing holding the metal tight.

Mig weld .250 on the inside of the two mig welds 3 inches= 2.500 or 1/2 inch of nothing holding the metal

If you do the math over a couple feet, theres quite a difference in what is sealed and what isn't.

Does anybody know what happens to this glue once you melt it with the mig, run out, get brittle?

Thanks Rob

 

"Restoration", hmmm, unless you dip the car, then paint it with an enamel primer and then lacquer paint, single stage, then get Mike over on Arrowhead street (an actual worker from the "A" body days at the GM plant here in Fremont) to come over and put his grease pencil mark on your firewall, you aren't "restoring" it back to original anyway!

How about plastic filler, there was none on those cars. How about a fender made in taiwan! They sure as heck didn't have that.

Come on, there is a middle of the road that we all follow on these restorations.

Dan, you asked the MANUFACTURER what to do. They said don't weld it, so don't.

Brian

 

Rob, just a small correction to your terminology. I know what you mean, it just may make it easier in the future.


0.187" is inches. In thousandth of an inch its "one hundred and eighty seven thousands of an inch"

If you say .187 thou you are really saying 187 microinches, or 0.000187"



Oh, and I think Brian was talking to you, not me, when he said don't weld.


In general:
I don't recall Rob even saying he was trying to do a 100% resto! Brian is 100% right, why allow body filler and modern paint chemistries and not allow bonding? Why allow radial tires, unleaded gasoline, and metallic brake pads and not allow bonding?

100% correct resto is something completely different, and in 99.99% of cases is impractical. How many 1000 pt cars have you ever heard of? If that is the goal then fine. Even so I would be tempted to use modern materials if they couldn't be seen (ie, epoxy primer, synthetic oil, and maybe even in certain areas panel bonding!!!).

In resto's I am more interested in the spirit of the endeavor, that is, bringing a classic back to life, than arguing semantics. Even if it is original in appearance and function, with increased longevity, I'm happy. I realize some people want to try and make a car EXACTLY like it was back then, and that's your business.

Whatever, I'm going home now.

 

I can see in twenty years, you will never learn.. Hey, if you dont like what I said then don't ask....

Oh, and one more thing:


MARTINSR has forgotten more about doing bodywork the proper way than most people, even people in the trade, will ever learn. Why else would his opinion be respected on forums all over the internet? And I've always seen him disclaim opinions as such when posting one as opposed to fact. Even people that have "been doing bodywork a long time" should never consider themselves as being finished with learning, and should be open to learning from other experts.

 

Some of us like myself don't have all the tools or knowledge to do a concours restoration, a lot of us only want to fix our cars or make them better. Anytime you mix in amatuers like myself in with professionals you can get a lot of different opinions.

I am however intelligent enough to know that I can and have gotten answers to my questions on this site. It isn't my intention to cause frustration, just remember some of us are here to learn, and If we don't ask questions or work in a body shop it's all trial and error. With the price of material, no body shop discount, that error can be very expensive.

Alot of us work alone and can't ask a coworker how he would do something.

But with all the people on this site, we can walk out of our garages and ask somebody on here.

To be able to use this forum is a privledge that I don't want to lose, so I will roll with the punches.

One more thing

When we get these cars done, and if they look good, you professionals should be just as proud of these cars as we are, because you were also a big part of it.

Rob

 

WoW what a thread!I like debate,especially with alot of information.On one of my first posts I guess I should have said as far as (I) stand "the jury is still out " as far as panal adhesives go,might of save a lot of scruntney.But Im glad as I acquired a lot of information.And I thank Dan72 and technova for that though am still going to "watch"for awhile.back to welding up 1/8 inch screw holes which will take one stitch weld,I believe it would get no hotter then using (strsw)when cooled right away with air from a airhose and would probaby heat up the same total area as the(strsw),its not like he is continuous welding the lap joint he just glued,just wanted to clarify that.

and on another note the last time I flew I looked out and there seemed to be some rivets holding them there wings together,nothing like looking out of an airplane at 8000 ft and seeing fasteners . when I helped build some of boeings stuff in one of there plants they had these big ovens called autoclaves that they "melted" plane parts together , the ovens were big enough to fit half a fuselage lodge ,dont know the whole process though its (top secret)LOL thanks again for the info guys and remember

 

Darryl


Thats quite a fleet of cars you have there, any pictures to share with us.

Rob

 

Ok Brian, ask Mike what he would do.......... (EDIT) (sorry I did some re reading and saw you said the same thing I am saying now.. BTW GOOD advice!)
Last time I checked........... This guy asked this forum for advice.............. I said in the above post, people loosely "restore their cars" Oh and it is a 100 point show car. Their is more then one way to do it. I use better paint and wheels and chassies components. but the way to patch a hole is with steel and welds. PEROID. You want to seam seal between the spot welds of two pnls, Cool that is a great repair. Oh and one more thing, I just started to re read this post just to brush up. look at brians first post to U........ looks like the same thing I said..

"I am sorry, I disagree. If you weld that hole with ANY kind of penatration the adhesive within a half inch of it is TOAST. Heat is "Kripton" to these adhesives.

If you are trying to bond a line that is then going to be seen like a seam from quarter to roof, I say you should be welding it anyway.

Why would you need to cover up the bonded seam, it is usually used on a pinch weld or something like that where it will not need screws."

Brian
__________________
Brian Martin