Thread: Weld and bolts vs Gluing panels, a science project.....

Tweet

Well, we have talked about this a number of times, can "gluing" panels on a car possibly be as strong as welding it on. Well, my 10 year olds science project may have the answer!

He cut 12 pieces of 20 gauge steel. We then welded them together in pairs. We butt welded with the MIG, "plug welded" with the MIG, spot welded with a $20,000 ProSpot STRSW and drilled 1/4" holes and bolted two as well. We then bonded with Winzer Universal Panel bonding adhesive another piece of metal to each of the pairs of welded and bolted sets.

We put clamps on them and pulled them apart using the Chief frame rack at work (10 year old boys love destroying things, don't they?).

Here are the results, the glue won every single time! Pretty impressive I would say.

Brian

Originally Posted by MARTINSR

....... (10 year old boys love destroying things, don't they?).

Not just 10 year old ones.............

Leave the glued panel out in the weather for a year or so and try it again, you'll get a big surprise!

your weld would have to run the same way your glue is filling up[ the joint .on the over lap . not just on one pull point in the middle of your test strip weld it along the front and along the sides or just put the glue on the same way your fixing the strips on. if you weld it in the middle you would have to do the same with your glue this way if will it have a start place to fail like your test strips with out the glue i would say that the spot welds will go with them set on one pulling plane and the bolts may not hold as well less you have big surface / washer . what i am trying to say is that you have a over lap joint with your glue and not with any of your welds or fasteners

Originally Posted by R Pope

Leave the glued panel out in the weather for a year or so and try it again, you'll get a big surprise!

i have used it in our bodyshop for 8 to 10 years , never had a problem .
we glue 1/4 panels, door skins , roof skins . take a car and weld a 1/4 panel on and try to corrision protect the back side where you cant get to .
i will take glue all day !

is that the point ?...welding a is not a glue . a weld on new car tin can be tuff .thin tin the glue would work as long as it will not go past the point were heat will affect the glue joint. or is heat set there have been better glue that have come out. but welding will bond into the tin the glue is just on the surface so the joint may move at a diferent rate and show on a painted finish joint

I like your project!

The glue probably holds about 2,000 psi in shear, or 2,000 lb per square inch of bond surface which is in the ball park here. The sheet metal will begin to fail due to bearing stresses from 2 x 1/4 inch bolts under 1,000 lb. Those welds did not appear to have much area to them either.

The achilles of bonded joints lies in tensile peel of the joint. In tension the bond is fairly weak. If you can avoid this condition they will work real good in general. If there is tension then glue it and bolt (or rivet) it. The old belt and suspenders trick works wonders. BTW a pattern of 5 x 1/4 steel rivets (like on a dice) would probably rival the glue.

Kitz

These responses are similar to the catalyzed primer comments on the 3k thread. Some folks have problems, others chime in along the same line. Not saying they haven't had the problem, just saying that the experience of thousands of others is different. In the case of catalyzed primers and panel bonding, the pros in body shops, other paint facilities, and even the OEM plants have success everyday with these products. They have an economic interest in success/performance because they have warrantees issued.

The DIY guy has a greater chance for failure for any number of reasons. Getting help is more difficult because they are "small fry" to the sellers of the material, and they are less likely (which is also to say not always) to store and use the materials correctly without realizing their error. There is also the chance that the material is out of date, contaminated, or otherwise environmentaly adversely affected. When I had my shop, if I had a product performance issue I would have a knowledgable rep at my door in short order to determine cause and remediation......................that's part of the benefit of spending many thousands per month for product.

I use the glue when it's a "stock replacement" type panel. However, most of my work is body mods on things that I just don't trust the glue....chopped tops, etc. For a plain old quarter panel R&R, I'll use the glue all the time. Never had any trouble with paint or anything else on the glued joints, just a matter of getting the fit and overlap right and following the manufacturer's instructions and recomendations. First panel I glued on, I had the rep right there helping!!!!

and if you can not weld ....it would fall apart too .so what is the point of the test?? i have no problem with a test at a over lap weld test like the glue. i have used glue on many of the new cars skins. but it would be hard to weld them on . it ,s still not welding ......

If nothing else, posting these results have provided me with some great discussion. Bob, you hit on something no one else has on a number of forums where I posted this. VERY interesting look you have there.

One thing is for sure, my 10 year old son using this stuff for the first time pulled it off. That tells me that outside of the posibility of product failure (I have to say is very rare) the learning curve was a heck of a lot less than welding!

And guys, it IS here, it IS holding everything from Fighter jets to hundred plus foot tall tv and radio antennas togther. On MANY factory cars there are bonded in floors, roofs and even frame sections. BMW has a factory recommendation for frame rail replacement where you bond the spliced rail together with not a single weld or bolt. This is in a 2006 5 series!

I found it interesting, and we plan on doing a few more tests with a Mythbusters FAIL BE DAMNED additude with less bonding area and more welds.

Brian

hot rivets ?? how many thing are still standing ?? and bolts and welds . can glue work as long as hot rivets?? No what about a bad glue joint from oil water bad glue old out of date ??? it could be said for welding and bolts but the bolt would be about the best for low skill ?? i would say less then any thing welding will take more skill but if you can not weld you should not fix it glue is here to stay and on new cars if they want you to fix them with glue than glue it but i would not try to glue a frame rail on a 57 chevy

Well, the projects were judged today by some out of town science guy and out of 60 kids he came in second! This was a BIG deal for him. He doesn't usually get very good grades and struggles a lot with school so this was a shot in the arm.

Brian

The Lotus Elise has a largely bonded FRAME. In a little search to find more info, I found some interesting stuff. A lot of these cars use a small amount of rivets or welds in conjuction with the bonding. But many structual parts are totally bonded in.



The Lotus Elise is a roadster conceived in early 1994 and released in September 1996 by the English manufacturer Lotus Cars. The car has a hand-finished fiberglass body shell atop its aluminium extrusion and bonded frame that provides a rigid platform for the suspension, while keeping weight and production costs to a minimum. The Elise was named after then Lotus' chairman Romano Artioli's granddaughter, "Elisa".





http://en.wikipedia.org/wiki/Lotus_Elise



"Unlike McLaren F1, Ferrari F50's rear suspensions are directly bonded to the engine / gearbox assembly. This means the engine becomes the stressed member which supports the load from rear axle. Then, the whole engine / gearbox / rear suspensions structure is bonded into the carbon fiber chassis through light alloy. This is a first for a road car. "



Lotus's technology was originated by its supplier, Hydro Aluminium of Denmark. Hydro discovered that aluminium extrusion can be bonded by epoxy resin (glue) if it is adequately prepared by a special chemical in the bonding surface. Surprisingly, glue can bond the sections together strongly and reliably. Most important, the aluminium extruded sections can be made much thinner than traditional welding technique. Why ? because welded joints are weak, so the thickness of material should be increased throughout a member just to make a joint strong enough. Therefore Elise's chassis could be lighter yet stiffer.



http://www.autozine.org/technical_sc...h_chassis2.htm

I think the project is great. Maybe not apples to apples but it shows the new technology, and for 10 yr old I say praise him. We need engineers, here is a beginner learing the trade. There are probably a few of us who remember when bondo came around. Lead was in and plastic was "new fangled junk". I even had HS auto class using lead. Never used it again. Ever hear of leadding now?? Lost art. good riddance.