I recently caught “Speedmakers” on Speed channel. It showed Aston Martin factory and how they glue body panels, they went on to say that it creates stronger bond than welding. Has anybody tried gluing any panels. I was thinking about using some high strength epoxy and gluing Engman inner long kit, it seems as a good candidate as the pieces are flat and fit flush. What do you guys think?

read and learn all about the adhesives...
Its pretty common to use panel adhesive for non structural panels...most cars are made that way nowadays.

For structural, I would not do it, but it might work with the right adhesive.

Do some learning on 3M's website....

Rich

Have you ever seen a Ford taurus driving around with no quarter panels? They're all glued on, but in perfect conditions. You must duplicate those conditions and that epoxy has no strength with a large gap.

this will be an interesting discussion. The body shop that did my 911 and 914 work (they turned my 911SC into a Widebody using Porsche metal parts and welded everything as the factory did) would like to use adhesives when I talked to them about putting the flares on my 914. He says it will be as strong or stronger then welding with no distorting of the metal from heat (he's used to adhesives as it's a corvette restoration shop).

I work at Peterbilt. serveral truck models are glued together, two part glue that is very strong. holds up on a Class 8 truck

I followed Rich’s advise and did a quick research on 3M website. I think that if they glue box sides, van sides, utility vehicle sides, then it’s pretty safe to glue Engman inner long kit. I guess it’s not that ridiculously stupid after all and I’m going to give it a shot.

Benefits are huge: eliminates risk of shrinking/twisting longitudinals, damaging heater tube inside long channel, damaging wire harness, fuel lines and whatever else is inside tunnel, no need to take out entire interior etc.
Another good candidate would be the battery tray.

For those who are interested:
1) Alphabetical list of products
http://www.3m.com/product/a_index.html
2) Adhesive, Automix Panel Bonding (pretty expensive)
http://3mcollision.com/3m-automix-panel-bo...sive-08116.html

I would really like to hear how this works out.
I am not certain structural adhesive can stand up (thus why car makers still weld the unibody)

For a fender...I agree it may be a better way to go versus welding.

Rich

As far as glue joints go, it doesn't get any better than the Engman inner long kit. It's a lap joint with a huge amount of surface area. My main concern would be rust weakening the glue joint. If you paint it your joint will only be as strong as the paint to metal bond.

Click to view attachment

Mmmmmm Glue

But here is a big advantage. With a clean surface, the rust won't form because it will be sealed. When welding these panels, you should use a weld through primer to prevent rusting between the panels. As far as the Engman kit being glued in, it might be a great way to go. If the glue fails, your car won't fall apart. It is a stiffening kit and not really structural.

Mark,
Great point. Check out this chart.

Directions:
http://www.3m.com.au/intl/au/auto_marine/a...g_Wallchart.pdf

Basic summary:
Surface needs to be stripped to bare metal. Thin layer needs to be applied to bare metal and will act as primer (9). Then 2nd layer needs to be applied.

The more i read about it, the more I like it. You can even spot weld through this stuff (6), then you may use weld thru primer.

Don't forget this: 3m Adhesive Gun

Wonder how much 200mL will cover?

$411.00 for 6 200ml packs. Makes the Engman kit look cheap by comparison. I still think this is a cool method. You can even spot weld through it.

THOMAS glued fiberglass flared fenders on his car. It worked great but he said you must make damn sure you have what you are gluing in the correct position because once the glue sets up it is ON THERE FOR GOOD. Having said that, I think I would rather weld the Engman kit on (which is what I did).
Cheers, Elliot

I think this was discussed before. I think the consensus was that gluing/bonding this piece is not the optimal way to secure since the two areas were not designed for epoxy bonding and the gaps in the panels will not be uniform. I think it would also be very hard to secure the reinforcement panel to the long and especially to the firewall while the glue dries.

What he said.

I bought a product called Fusor made by Lord Industries. I used it on my bus when I replaced the long rocker panel on the left side. I was affraid of having major warping welding on such a long peice. Worked great! However, it needs to be clamped tight for it to hold. I glued two 1" strips together and could not tear them apart.

You can vacuum bag it easy. I've vacuum bagged heater blankets onto airplane wings. Get some vacuum tape, thick plastic and a vacuum pump or the cheaper venturi vacuum generator. Way better than clamps and you'll have equal pressure on every square inch. It'll suck the metal down tight.

You can use 1/8" self tapping screws through both panels to bind them tight and then remove them later and glue the holes shut. Way faster and way cheaper than those silly Kleco fasteners.

I am using the 3m panel bond adhesive on my fiberglass quarter panels. I used the self tapping screws and filled holes with the adhesive when they were removed. The thread is here, I don't know how to attach it to this. It is titled "on the ground". I bought all mine on ebay for 40.00 per unit. I may be selling the applicator when I finish!

I was browsing sheet metal selection and it occured to me that since I won't be welding it, I can use galvanized steel which will last far longer than weldable steel.

And the alternative is...?

I say go for it! Just take many pictures. The worst that could happen is you have to weld them later.

Yup! I would use a lot of them.

You would need the special glass welding rod.

Since the glue is so expensive, I would identify any places where the gaps would so wide as to not likely be glued and paint those areas. Use the glue only where it will be effective.

I agree with all the application ideas above. I went to my oldest son's wedding at the house of his new wife's boss who does non destructive quality control of new products. He does lots of structural adhesive testing and said the main thing would be to get the glue to come out all arournd the edges and holes of the engman panels eliminating any voids, and pull them down good with screws and it should be forever. Remove the screws and plug the holes, i would use a epoxy for the holes myself not the adhesive, the part I like is no heat on the existing metal.

We had this discussion maybe a year ago.

I don't think the last time this was discussed was even a year ago. About the only draw back I could think of by using panel adhesive system would be when a small repair may be required. It would not be a small repair, the whole piece (the whole area that is bonded together) would have to be replaced. In the case of the long, a small section repair (Hmmm, maybe nobody has ever slid into a pole in the door area) would not be possible. Cars and trucks are not the only things that are bonded, ever check out an Airbus? I know of a rear horizontal stabilizer sitting on a flatbed trailer waiting for a "certified" repair process. Those assemblies are bonded and certified when manufactured. Composite materials are used but still, bonding is used as an assembly procedure.

Ok I missed the time frame a coupla weeks.

http://www.914world.com/bbs2/index.php?sho...106792&st=0

You're right, it will be tough to eliminate all the voids caused by holes and/or fill holes. I will have to make replicas w/o holes. What's good place to buy sheet steel? I'm going to go w/ 16ga galvanized.

PS. Sorry for

It's not tough at all if you use a vacuum bag. I've done hundreds of these glue ups on commercial aircraft. Most were on the wings that see huge amounts of flex and wind shear without failure. Any hole in the panel your installing will actually help eliminate voids and suck out excess glue.

I’ve been doing this gig for a long long time.

1) Bonding non structural panels is an acceptable practice.
2) Bonding structural components like steel rails is not. Composite tubs are another animal. Manufacturers such as Mercedes bond composite trunk floors to steel sub-structures on almost every new model now.
3) A lot of manufacturers use a process called weld-bonding. Adhesive augments the weld strength. This is where a weld such as a plug, resistance or laser weld is done through the bonding material. Very common on center pillars, rockers, unisides and floors. See a lot on aluminum based chassis's.

Bonding performs very well in shear. Excellent fatigue resistance due to a larger load spread throughout the mated components. High viscoelasticity.

The downside of structural bonding is low peel strength with components that are out of plane. Large panel gaps tend to be problematic versus tight fitting joints. Joint strength is dependent on surface area bonded.

ALCAN has done extensive research with welding and bonding of aluminum. The process of weld bonding aluminum came about because the metal to metal welds or through welds acted as clamps or tacks while the adhesive cured. The metal welds also increased peel strength dramatically. Bonds also reduce oxidation at weld sites. Resistance welding of aluminum has a high tendency to crack at weld locations. Welds combined with bonding average a 23% increase in the force displacement curve.

Most of the auto manufacturers use a product called Betamate 4601 in the manufacturing/ bonding process. It is a single part adhesive. When the aluminum BMW 5 series vehicles are manufactured or repaired the recommended cure cycle is 175 degrees for 30 minutes. The only way you can get that is with a heated spray booth or flame.

For the 914:
When I installed the rear trunk floor I weld-bonded three sides at the Trans cross member and wheelhouses. Why? I was experimenting with Wurth's Power Bond. The electric welds were enough. I just did it anyways.

Would I bond the Engman Kit? I would not bond alone because those longs flex, bend and twist. I would definitely supplement the welds with bonding though.

The fillers for the air distribution system ducting cut outs were all bonded. I used ultra thin aluminum sheet with a medium strength adhesive. Fast, easy and clean. Another area where bonding has advantages... dissimilar metals. Not structural but clearly efficient.

Some but not all structural adhesives need heat. Heat is generated as part of the chemical reaction of the epoxy. If required I added a heater blanket to the vacuum bag. Not cheap if you need custom sizing.

http://www.atacs.com/media/html/product.ph...;product_id=364

Personally I'd weld it. I do dig the idea of no chance of heat distortion to the metal. I think Jeff's combo weld/bond idea has the most merit.

Galvanized steel is zinc coated, and it can be problematic to get things to stick to it.

Tell me you have never seen a car in a parking lot with delaminating paint.

Special problem needs special solution.

"Henkel Corporation has introduced Loctite® H8600™ Speedbonder™, a structural adhesive designed for superior bond strength on difficult to bond galvanized steel. The product also offers excellent results bonding steel, aluminum, stainless steel, polycarbonate, fiber reinforced plastic (FRP) composite, and Gelcoat."