Adhesive for Aluminum floor to steel tube

[pakracer]

Wondering about what is the best adhesive to use to bond aluminum floor pan to steel tube, will be riveted at the same time. And any prep to be done to steel or aluminum. I'd like it to be able to be done without exotic materials or process's. Thanks

[BeerBudgetRacing]

Hysol E-120HP

Search for Belly Pan replacement here. Lots of info on rivets, prep, etc.

[Mike B]

Plenty of threads on here but this article is a great summary and has all the info you need:

https://www.apexspeed.com/features/bellypan/

[S Lathrop]

I have use Loctite 9460 Hysol.

What I have learned is, that with 1" square lower frame rails, I needed to double the bonding area of the bottom of the frames. I add a 1 inch wide strip of steel to the inside to the bottom of the frame rails. I then use 4 rows of rivets that are spaced 1.5 inches between each rivet in a row and the rows are are staggered. The end pattern has 2 rivets every 3/4 inch longitudinally along the frame rails and 1 inch side ways between rivets.

Bonding to 1" square rails only lasted a couple seasons at best, With the rivet strips and the 2" wide bonding area I have not had to redo a belly pan unless I was repairing damage.

Also in doing torsion tests on frames, the wide bonding area adds maybe 20% more stiffness to a frame than the traditional belly pan setup. Now I did increase the belly pan from .060 thick to .080 thick.

[pakracer]

Info is helpful and just what I needed Thanks Pete

[bassracer]

I recently followed Mr Lathrops advice. It was a long process for my first time but we are happy with the results. And I really hope I don’t have to pull the pan sooner than 5 years.

[Earley Motorsports]

Hi all. Is it worthwhile to bond an aluminum floor to a round tube frame. Is there enough surface contact to make a difference. Thanks in advance for info.

[S Lathrop]

Hi all. Is it worthwhile to bond an aluminum floor to a round tube frame. Is there enough surface contact to make a difference. Thanks in advance for info.

Unless you can form the aluminum around the tubes, you don't have enough bonding surface.

I would think that there might be a safety issue with a belly pan that was only fastened to the round tubes and was not formed around the tube. I think that there is a significant probability that the edge of the belly pan could contact something likt a speed bump, especially if the car were traveling side ways. In that case the belly pan might be pealed back exposing the driver of the fuel cell. I have had this happen. I have had issues like this where the belly pan has been pealed away from the frame.

The one car I owned and did have a big crash in was a Titan Mk 6. That car had the lower body work go from the upper frame rails on both sides and around and under the frame. That seemed to work well but the lower body section took a lot of maintenance.

[jrh3]

I have use Loctite 9460 Hysol.

What I have learned is, that with 1" square lower frame rails, I needed to double the bonding area of the bottom of the frames. I add a 1 inch wide strip of steel to the inside to the bottom of the frame rails. I then use 4 rows of rivets that are spaced 1.5 inches between each rivet in a row and the rows are are staggered. The end pattern has 2 rivets every 3/4 inch longitudinally along the frame rails and 1 inch side ways between rivets.

Bonding to 1" square rails only lasted a couple seasons at best, With the rivet strips and the 2" wide bonding area I have not had to redo a belly pan unless I was repairing damage.

Also in doing torsion tests on frames, the wide bonding area adds maybe 20% more stiffness to a frame than the traditional belly pan setup. Now I did increase the belly pan from .060 thick to .080 thick.

Any thoughts on using 1x1 aluminum angles. Bond and rivet to the belly pan and vertical inboard element of the lower sq tube frame rails. Referring to 1x1 square tubing. Riveting angle instead of welding 049 strips. Most applicable on bays without cross bracing.

[S Lathrop]

Any thoughts on using 1x1 aluminum angles. Bond and rivet to the belly pan and vertical inboard element of the lower frame rails.

The angle would give double the attachment but it would not help the problem of snagging an edge of the belly pan.

I would try to form the belly pan around the lower frame rails. You might have to use an aluminum alloy like 5052 that will form easier than 6061.

Does your car have bracing between the lower frame rails or is the belly pan intended to be structural to the frame?

[bassracer]

Continuing to attempt to apply the advice of Mr Lathrop. Completed side pod floor mounts with angle strips vs the original extended belly pan.

[Earley Motorsports]

Thanks all for the information. As this was the only formula ford built by Bob Riley I will leave it as it was. The way he did the floor is pretty cool. Thanks again.

[Craig Henry]

Hi Everyone,

The (3) 50 ml cartridges of Hysol E-120HP I purchased a few years back have expired and my frame is finally ready to attach the new floor pan thus I need to purchase more epoxy. Yesterday, I re-read a couple of decades of posts on the topic but there was no consistent answer as to how much epoxy is needed. Ranged from just over (1) 50 ml cartridge to (5) plus 50 ml cartridges.

Knowing having too much is better than running out, how much do I need?

Data:

RF92 FF frame with the added 1-inch internal strips (looks just like Brandon’s frame posted here.)

I have both 50 ml and 200 ml cartridge dispensers.

Epoxy:

Hysol E-120HP seems to be the overall favorite but I’m leaning towards using Hysol EA 9460 if I can convince myself the 50 minute (versus 120) working life will not be an issue. I have a pneumatic riveter for pull rivets, but I don’t have a ton of experience bucking rivets. Also, I will have a helper. Opinions?

Thanks in advance for the help.

Craig Henry

[S Lathrop]

Hi Everyone,

The (3) 50 ml cartridges of Hysol E-120HP I purchased a few years back have expired and my frame is finally ready to attach the new floor pan thus I need to purchase more epoxy. Yesterday, I re-read a couple of decades of posts on the topic but there was no consistent answer as to how much epoxy is needed. Ranged from just over (1) 50 ml cartridge to (5) plus 50 ml cartridges.

Knowing having too much is better than running out, how much do I need?

Data:

RF92 FF frame with the added 1-inch internal strips (looks just like Brandon’s frame posted here.)

I have both 50 ml and 200 ml cartridge dispensers.

Epoxy:

Hysol E-120HP seems to be the overall favorite but I’m leaning towards using Hysol EA 9460 if I can convince myself the 50 minute (versus 120) working life will not be an issue. I have a pneumatic riveter for pull rivets, but I don’t have a ton of experience bucking rivets. Also, I will have a helper. Opinions?

Thanks in advance for the help.

Craig Henry

50 ml is plenty. I have always used 9460 and the cure time has not been an issue. Given that it is winter now, just turn the heat down and you will have plenty of time to get the solid rivets driven. The other trick is to keep the epoxy cool when you start using.

You might want to practice driving the solid rivets. I use a regulator on the air line and set the pressure in the 30 to 40 psi range. I use a rivet gun but you can use an air hammer, just turn the air pressure down a bit.

[Charles Warner]

Steve,

What is your opinion of steel pin-drive rivets as opposed to bucked solid rivets?

And, do you use a different epoxy bonding aluminum to aluminum? If so, what is your preference?

[S Lathrop]

Steve,

What is your opinion of steel pin-drive rivets as opposed to bucked solid rivets?

And, do you use a different epoxy bonding aluminum to aluminum? If so, what is your preference?

The rivet holes are countersunk on the bottom of belly pan so I have a smooth surface on the bottom of the car. The solid rivets have the dome heads inside the cockpit which makes fo ra nice look. Bucked end of the rivet is driven into the counter sink on the bottom of the belly pan. I also have a rivet shaving tool so I can make sure the driven part of the rivet is flush to the bottom of the car.

One reason I do it this way is that we often have a flat piece of steel glued and bolted to the bottom of the car for ballast. So I need the bottom to be smooth.

When I was building aluminum monocoque tubs for the Zink Z14 we used epoxy adhesive for all the joints of the tub. That allowed us to almost double the time we got out of the tubs before we had to take them apart and red the joints. Doing the belly pans as I do now we are getting decades out of the floor pans before we need to think about redoing the belly pans.

[DSR3]

'just did mine a couple weeks ago (solo).
Suggestions;
-Cleco clamps
-Spare rivet gun
-Epoxy in duo-pack and THE CORRECT plunger/gun and mixer-tips

[stonebridge20]

'just did mine a couple weeks ago (solo).
Suggestions;
-Cleco clamps
-Spare rivet gun
-Epoxy in duo-pack and THE CORRECT plunger/gun and mixer-tips

The spare rivet gun is a really good idea.

A few weeks ago we started on a floor pan and the rivet gun took a dump on about the 20th rivet. Luckily I had a second gun and was able to pull the other 520 rivets before the epoxy started to setup.

[bassracer]

Steve,
What is your opinion of steel pin-drive rivets as opposed to bucked solid rivets?

When I did mine, I was very intentional about sticking to the school of Lathrop as possible, however I interpreted the solid rivet application differently - we just bought CS solid rivets and bucked from the inside of the gusset strips and still maintained a flat bottom.