Structural Foam Injection

[doug73cs]

I've found suppliers for structural foam used by Ford and Lexus to add stiffness to ABC pillars and sills and understand the general procedure for doing this but some first hand experience would be appreciated. The expansion factor inside A and C pillars in particular, prepping for the injection (POR-15 maybe?) and any helpful hints?

I believe someone named Fred has done this but anyone else with experience comments would be appreciated.

Doug

[bobthomas]

No experience with this but I would think you need to be sure foam has "an out", somewhere to escape to as it expands. Wouldn't want to split or otherwise deform the part you're trying to strengthen.

[TKMad]

I have done it to my 02 with excellent results. I used 2 part 8lb urethane foam from US Composites as well as some 2lb foam from Handi-Foam.

Basically I filled the sills and front frame rails with 8lb by pouring it into holes that already existed. Pretty straight forward but a little messy. Then I used the 2lb for the A and C pillars, as well as the structure around the roof. It came in a pressurized dispenser so it was quite easy.

The foam is completely water proof so I'm not worried about corrosion and it is fire resistant as well, much better than fiberglass. The down side is that it will make future structural repairs more labor intensive. If you get in a wreck, for example, you would have to physically remove the foam from the area before welding in a new piece. Not a big price, but it certainly isn't free.

The result is amazing. Much quieter ride and I don't feel any body flex at all. I have a very sloped driveway and when I used to turn into it the would creak and groan. Now it is absolutely silent. I would estimate I added about 16 lbs to the car and it cost me about $100. Took a weekend to do it.

I would add pics if I had them but there isn't much to see other than holes filled with foam.

[nbcbird]

I have posted here several times about using expanding foam (used in house construction) in my rocker panels and rear shock support void (accessed from the rear seat area). It weighs very little. My thinking was to keep air from entering these cavities and avoid further rust--along with some possible structural advantages. Before foaming, these areas were given a thorough application of a rust preventative that formed it's own coating (from NAPA IIRC), and allowed to dry thoroughly. I am not a fan of POR15 which is formulated to be applied over rust. I applied foam over ten years ago and haven't experienced any rust deterioration since then. One might also think about using foam in the rear subframe cross-member. I couldn't believe the amount of rust in it's interior when I removed it for powder coating.

[Colin]

I've found suppliers for structural foam used by Ford and Lexus to add stiffness to ABC pillars and sills and understand the general procedure for doing this but some first hand experience would be appreciated. The expansion factor inside A and C pillars in particular, prepping for the injection (POR-15 maybe?) and any helpful hints?

I believe someone named Fred has done this but anyone else with experience comments would be appreciated.

Doug

Can you please share your source with the foam?

[doug73cs]

Thanks to all for the comments. On my list of things to do before the headliner goes back in.

Colin - just type in structural foam on any online autobody products retailer search function and you should get something. DOW Chemical supplies a lot of the OEM foams under their Betafoam line of products.

http://search.store.yahoo.net/yhst-61185342264016/cgi-bin/nsearch?catalog=yhst-61185342264016&query=structural+foam&Go.x=0&Go.y=0&Go=search

Doug

[Colin]

Is there good access to the frame rails under the doors? If not, do you think it would worth drilling some access holes to get that filled up?

[Guest]

I have done it to my 02 with excellent results. I used 2 part 8lb urethane foam from US Composites as well as some 2lb foam from Handi-Foam.

Basically I filled the sills and front frame rails with 8lb by pouring it into holes that already existed. Pretty straight forward but a little messy. Then I used the 2lb for the A and C pillars, as well as the structure around the roof. It came in a pressurized dispenser so it was quite easy.

The foam is completely water proof so I'm not worried about corrosion

Did you just do the frame rails or the rockers too? I'm wondering because I've got my car very much apart right now and it would be a good time to do the rockers, but I don't know the volume of foam I'd need.

You mentioned ~16lbs/$100. I'm guessing you ordered a 16lb kit of the 8lb foam?

http://www.uscomposites.com/foam.html

Is this the 2lb foam you're talking about?

http://www.grainger.com/Grainger/HANDIFOAM-Foam-Kit-4KK28

Finally, I think the water proofing issue isn't with the foam. There will likely still be gaps somewhere that moisture could get to and the foam could accelerate rust if that's the case since it prevents it from exiting as easily. I think this would be a bigger problem with sunroof cars than with non sunroof cars.

Edit: just found this link which should answer most people's questions, it answered mine.

http://octanereport.com/tech/parts-reviews/2009/08/05/how-to-cheap-diy-foam-chassis-stiffening.html

[TKMad]

I have done it to my 02 with excellent results. I used 2 part 8lb urethane foam from US Composites as well as some 2lb foam from Handi-Foam.

Basically I filled the sills and front frame rails with 8lb by pouring it into holes that already existed. Pretty straight forward but a little messy. Then I used the 2lb for the A and C pillars, as well as the structure around the roof. It came in a pressurized dispenser so it was quite easy.

The foam is completely water proof so I'm not worried about corrosion

Did you just do the frame rails or the rockers too? I'm wondering because I've got my car very much apart right now and it would be a good time to do the rockers, but I don't know the volume of foam I'd need.

You mentioned ~16lbs/$100. I'm guessing you ordered a 16lb kit of the 8lb foam?

http://www.uscomposites.com/foam.html

Is this the 2lb foam you're talking about?

http://www.grainger.com/Grainger/HANDIFOAM-Foam-Kit-4KK28

Finally, I think the water proofing issue isn't with the foam. There will likely still be gaps somewhere that moisture could get to and the foam could accelerate rust if that's the case since it prevents it from exiting as easily. I think this would be a bigger problem with sunroof cars than with non sunroof cars.

Edit: just found this link which should answer most people's questions, it answered mine.

http://octanereport.com/tech/parts-reviews/2009/08/05/how-to-cheap-diy-foam-chassis-stiffening.html

Yes, I got the 16lb kit and had about 1/4 of it left when done. I used this light foam:

http://www.appliedenergyproducts.com/handi-foam-ll-22-two-part-foam-kit.html

That's twice as much foam ans the Grainger kit for the same price.

I did both the frame rails and the rockers/sills.

[Simeon]

They used to do this on Minis in the 60's. It used to cause all sorts of problems as it would hold moisture right up against the panel sides rather than letting it run down and escape from the bottom. Plus, as has been pointed out, welding repairs is then made tricky by it's presence.

I am not saying the stiffness isn't attractive and I am not saying that Ford don't know what they are doing but I would be concerned about any home made equivilants that are installed without understanding the full process used in the Ford factory.

Just saying...