Using an epoxy glue for structure

I am almost to the point of installing my floorboards in the coupe. Last night I did the lay out on my new found template material. The floor will end up being one continuous sheet and so I started thinking about how I would weld it all together.

I have been pondering using the skin adhesive that some bodyshops are using in collision repair etc. The problem is that most epoxy kits are used in small quan***ies. Anyone have any ideas on what a guy could use for larger areas?

Now before ya'll all start beating on me for using adhesive over welding, lets back up. I did an experiment 7-8 years ago on the Fly. We reskinned the doors using nothing but adhesive. No welds...anywhere. So far it has held up like a champ so I am sold.

The advantages are I can paint the floorboards and all of the structure before I install the floors. That way I have maximum protection from rust and it would minimize rattles, vibration etc.

Gimme your thoughts, good or bad.

 

Not sure what you mean by epoxy kits are used in small quan***ies? Most automotive epoxies come in different speeds so you could get one that would easily give you enough work time to do the floor boards even if you needed multiple tubes of product.

 

root, you need to look at 3m 08115 panel bond or the fusor equivalent. only problem is you will have to buy the gun to use either product. fusor guns seem to be cheaper, at least where I work. check your local supply house or pm me for availability

 

There are some companies like Evercoat & Wurth that are making two part adhesives that work in regular Caulking guns. No need for specialized guns.

 

Sounds like it would work and actually it's a good idea. Not sure what you mean about small quan***ies?? Doesn't fusor make different size tubes??

 

How much area will one of those usually cover? They are pricey, yes?

 

3M DP110? I know where you can get some.

 

Get back to work slacker.

 

Are you just doing the edges? I found the Evercoat ones to be about 20% less than 3M or Fusor and actually have a little bit more material in them. A couple of tubes max should do most floors. In Canada the Evercoat ones go for about $40.00 a tube.

 

the 3m automix epoxy is good for outer body panels, not reccomended for structural use. the gun is expensive.

 

I use 3M panel bond adhesive i believe its #8554 gives you plenty of work time and is very strongand it comes in a double tube with a self mixing nozzle,goes in a gun like a caulking gun. we use in the last body shop i worked in to put truck bedsides on and van roofs. this stuff is awsome just grind to metal where the adhesive is going to be.

 

I might be able to borrow a gun.

I guess I should clarify. It's not really structural. The floor has more than enough bracing. Overkill most would say. I just want bond it to the substructure, so the load would only be in compression. No shear load.

 

Sirleadfoot's right its 08115.

 

i've used that bonding adhesive on unibody cars that you don't get a lot of flex, the stuff works great. i ***ume that you are doing floors in a car with a full frame? i've never done this on a full frame car, but just to be on the safe side, i would a least tack weld the floor in 6 inch increments after the floor is bonded. don't know if it will split when you jack the car or put it on a lift. also if you are putting the floors right to the insde of the rocker panel, i would not recommend it at all. the body will twist to much and you could end up doing more damage than good. i hope this helps you with your decision.

 

I bought a tube of Fusor that fits in a standard caulk gun. It was $14. Kind of messy. Not sure how it holds up though. I was using it for a small section on the inside of my quarter window where it met the roof. It was next to impossible to get in there with a welder.

 

Rubber Seal sells some excellent structural adhesives, and they are priced right too, around $25 a tube...

 

Frame flex on a fully boxed and X-membered hotrod frame is probably not an issue.
Original frames were flexible for a reason, poor roads and driving conditions, and that has been eliminated from our list of problems in most plasces in this country.

 

that's not how they did it in the 50's.

 

I'm a 68 model, so I am exempt.

Aicraft guys, I have also pondered using some PS-890 we have that is out of date.
http://www.bergdahl.com/PS-890.htm

 

If your going to use panel bonding adhesive, check the manufacturors web site for the details of useage and application. Structural adhesives are used in almost all seams and joints in many of todays autos. It actually is applied to the hem flanges of most floorpans and structural rails , spot welded together and then cured in the paint baking process . This is one of several ways they increase the torsional rigidity of todays autos. You will need to hold things together under some sort of clamping till dry. Be aware that temperature is important in the curing process and if temp gets below 45 degrees it will not cure. Most need 24 hrs @ 72 degrees or can accelerated with short wave infared.

A couple of hints from the training cl***es we attended. Make sure the mating areas are free of all rust , dirt , oils and especially and dust as this will affect the adhering of the materials. Apply the material to both bonding flanges and squeege onto surfaces to ensure full coverage between mating surfaces.

Its great stuff but you may want to put a couple of plug welds in key places.

This link to ICar outlines a repair utilizing bonding adhesive. Its from 2002 and there mat be newer on the 3m or Fusor site.

http://www.i-car.com/html_pages/tec...e/advantage_online_archives/2002/082602.shtml

 

Dare I suggest something along the lines of PC-11? It's marine quality, available at most every reasonable hardware store in small quan***ies, in putty form that's easy to spread and works good on metal.

It dries pretty hard though and may crack if there is any severe flexing. Just a thought... I'll get back to my lurking...

 

PC-11 is more for small repairs I think. This will have miles of surface area. It starts at the firewall and ends at the tail lights.

Thanks Larry, I'll read up on that.

 

The advantages are I can paint the floorboards and all of the structure before I install the floors. That way I have maximum protection from rust and it would minimize rattles, vibration etc.

I would have never thought of using epoxy, I like the concept but how do you plan on executing?
I woud think it needs to bond to bare metal, corrosion protection would came from the epoxy itself in the joint?

and be held firmly to the substructure, so how do you spread the epoxy, clamp it to the contours and weld thru the epoxy, or plug weld it first and then how do you get the epoxy on the surface?

is it a surface spread type of application?
Watching and learning....

 

Root Hawg, I'm working on the floors on my coupe and was wondering if you have a picture of this one pc. floor of yours, and what gage material you used,
Grits

 

In case anybody has not seen one, A Double barrel caulk gun used for specialy packaged two part products

 

I was planning on not welding at all. If I decide to weld it. I'll just weld the whole thing.

Here was my plan.

I built a full scale template of the floor, 1 piece. It will have all holes located and all of the pieces trimmed where necessary. The floor sub structure follows the frame x member as well as having cross braces strategically placed through out. These sub structures , along with a roll bar are welded in place to the body structure.

I figured there is no way the floor could ever come out anyway, so welding it would not be necessary, other than to keep it from rattling. I was going to drill this floorpan and cleco it, to remove all wrinkles and keep it located.

Remove the floorpan, clean and prime, then paint the pans and the substructure. Then bond to the substructure while clecoing in place until dry. I will also have sandbags etc to hold it flat while bonding. Remove the weight and clecos a few days later and then throw some blind fasteners (pop rivets) in the cleco holes.

Edge seal all joints to prevent moisture from getting trapped in any voids.

Make sense?

 

Grits, I can take some pics tonight maybe.

 

Make sense?

Sounds like great idea!

Does it need to bond to bare metal to bare metal,
Would you tape off the bonding area, then touch it just touch it up after wards?

 

I don't think it has to be bare metal. On aircraft we use it on painted surfaces, it is more elastic than the stuff used in automotive. I would probably put it on with a gun, then spread it with a spatula. Then edge seal the substructure (after taping it off) touch up the paint.

I am trying to avoid the harmonics that come with all metal floorboards on all metal substructure.

 

With that glue can you mix any metals together? Like make a floor out of aluminum or something?