Thread: Foam Filling the chassis......

Please elucidate further on your experience and background. You sound like this ain't your first rodeo by a long-shot.

"Completely sealed", so if the...front rails had existing OEM holes in them, that would make them extremely difficult to foam? Is there a way to temporarily cover the holes (duck tape them bastards) until the foam quits expanding? Other than welding metal over the holes?

Keep in mind the foaming will be done before the car is even primered. Therefore, some "excess foam removal" or spillage is not dead critical. I know that Sal (body shop dude) and myself both want this process to be both as hassle-free and effective as possible. Now, I am picturing the foam expanding out of one (or more) of the OEM holes, becoming hard as rock, and sitting there like a gigantic wart on one of my front rails. Us getting out a chisel and a hammer.

I have already looked at the B pillar. That damn thing has HUGE OEM holes in it.



The car is dry as a bone. It has not seen the weather in four months or more. Parked inside, windows down. There should not be any moisture trapped anywhere. I hope.


No worries. Wheel to wheel racing will never, ever happen. Auto-cross in the future. I would love to go bomb a road course sometime. But not with other vehicles around in any type of head to head or wheel to wheel type racing. Just for fun and the learning experience.


You just did the frame rails alone? Both side rails and the front rails?

Therefore you left the A-B-C pillars foam-less? Yet still had excellent results?


I notice that the Foamseal stuff looks like it comes with an "applicator" nozzle. The US Composites stuff is a "mix and pour."

Why did you like the US Composites stuff better? What were the differences between the two foams?

I planned on calling the Houston distributor for Foamseal on Monday. I finally got their phone number from fomo.com, and planned on picking it up and delivering it to the body-shop.

I am foaming the chassis, no questions.

Please educate me further, before I pull the trigger on either product.

A few years back I went through and did a series of projects involving two part polurethane foam. Long story short, these included making custom molded seat inserts and running chassis foam through the B14.

The key thing about polyurethane foam is that it pours like 40 weight oil when you first mix it. Duct tape will help seal some smaller gaps, but it won't do for larger holes, especially those on the bottom of whatever open cavity you're filling. Wooden cutouts cut to fit those holes (then sealed off with gaffer tape) worked ok for the lower chassis. You may need to get creative if you really want to do the pillars.

Because of this, I ended up foam filling just the side rails on the B14 (the ones underneath the door), using the US Composites 8LB stuff. The difference in doing just that was fairly remarkable. The chassis felt more substantial, almost like one from a much heavier car.

The primary differences between the two types of foams are in the packaging due to application. The FoamSeal stuff is technically insulation foam, where the two part pourable foams are used for molding. Specificially, the two things I didn't like about the foamseal stuff was its lower density and the fact that the product is slightly aerated when it comes out of the applicator. This means that the finished product was less consistent in density and it was much easier to create air pockets in cavities.

Speaking of which, I should point out that, contrary to what was said earlier in this thread, using a lower density foam will not help prevent bulging out metal cavities. In fact, you actually increase the risk of doing that by using the low density stuff, as lower density foams expand more than the higher density stuff.

What you should do to prevent this is to mix small amounts and work in layers. That is, pour in a small amount, let it fully expand (but not cure), then pour in the next layer. This not only ensures that there is enough space for air to escape, but it also helps reduce spillage from overflow.

What I would recommend (if you're serious about doing this), is to get small samples of both and play with it firsthand. It'll save you a lot of aggrivation down the line.

i think the reason no one has done this is because its very un known! it has NEVER been covered in a magazine. there is no "step by step" online. no one that has done it to a b-chassis car has anything more to say about it other than "yea it helped alot!"

i mean no one really has a god damned clue what they are doing. and i know i wouldnt want to spend $100+ on a bottle of foam, have it turn out to be the wrong stuff, then not put it in all the right spots or encase a wire loom in a tomb of foam.

shawn........out of everything you have done for the community this would very likely be THE BEST THING EVER. to photo document this process down to the T. your name will be known world wide for your efforts.

Not only do I really want to do this, I want to do it thoroughly and right.

Wooden cut-outs, huh? Since the car is at the body-shop, I could also talk to Sal about any spots that would be easy to cover with welded-on steel sheeting. Since it was not covered in the original estimate, I would pay them extra if it would really help to break out the welder in some spots.


That is good to hear. However, I *think* I want to push it a step further. Those front rails are just begging for foaming, along with my Stephens Fender Braces and Cusco FSTB, that will effectively box off the front end. Not to mention, if I can get those A-B-C pillars done effectively/substantially.

I want the chassis and cabin interior to feel like a new vehicle. Better than most new ones. Tight, quiet, creak and rattle-free.


Gracias! Appreciate the insight.


Well....that makes sense.

Keep in mind, I am no expert on anything mechanically related.


OK. Slowly building-up layers inside the cavity in question.


Done. I'll get both tomorrow (today, when I wake up). Might have to order one out of town. Whatever, I'll get them both. Once in hand, I'll grab my camera and bring them to Sal. Then he and I can experiment first, before we (he) does the chassis. And I'll order whatever he thinks will work best given the structural members we are trying to fill.


Well, Mike K did his 300zx in SCC. However, that is the only time I have ever seen it in any magazine. It was also helpful, but a long way from an actual step-by-step.


I understand where you are coming from.

However, for me the cost is neglible at this point. Even if I have to pay for more time from the professionals, buy "experimental" batches of two (2) different foams, and then the correct amount of the appropriate foam, or foams plural. I'm real determined on this particular aspect of the vehicle.


Thanks, exhuberant and high praise indeed. I was merely thinking that I finally have a thread to add to the Suspension Thread that I actually started. I think it's my first.

However, I am merely following what Mike K (choaderboy2) and Steve (98sr20ve) laid out for me. I'm just gonna spend money, shoot photos, and chronicle the events.

Right after ordering foam(s), I'm going over to Shepherd Square. Check on the mechanical progress. I'll take some detailed pics of the frame rails and pillars. Maybe measure some of those holes that would have to be filled. Get a plan of attack together on effectively closing as many of those holes as possible while we, meaning Sal, foams for maximum results. Hell, I can do wooden cut-outs and gaffer tape. I'm actually handy with a jig-saw.

This is gonna be a pain in the ass, but fun.

Oh, one last note before I forget. You will want to seal up all of the pinch welds on the chassis (side rails, underside of car) with gaffer tape or gorilla tape before you put foam in them. None of them are sealed very well and foam will escape through the gaps.

Aha...thank you again.

Gaffer tape I am familiar with, I used to work in SLV (Sound, Light, and Video) contracting. Theatrical stuff, very strong, made of clothe. Gorilla tape I have seen at Lowes. You are being specific on those tapes, will duct tape not work? If so, why?

I am also thinking that no matter the adhesive on the tape, clean-up will be fairly straightforward, because no solvent will (can) harm the foam material.

Please understand that I am grilling you on as much as possible, so I don't have to find out the hard way.

__________________________

1) And now to call "Specialty Products & Insulation," located right here in little ol' Houston. The Foamseal folks.....then off to Shepherd Square to really examine those rails and pillars.

Specialty Products & Insulation
2500 Fairway Park Drive
Houston, TX 77092
713-957-2730

Customer service rep Jeff helped me out. I can buy one cubic foot of this stuff, p/n P10600 for $36.48. I have to order it, and it will take "about a week" to get it. I'll go pay for and order it tomorrow morning. That will give me and Sal some test-product to play with.

BTW, p/n 10650 is $60.91 from Specialty Products & Insulation.

2)


They sell directly to the public. So, I ordered via credit card. It will arrive end of this week, early next week.

Then Sal and I can start playing "Play-Doh" factory with the two (2) different foam products.

_____________________________________________

A hundred bucks worth of foam into it already. ....

I really don't give much of a sh*t. Did I mention that I am real determined on this one, and a hundred bucks, relatively speaking at this point, is a drop in the proverbial bucket?

Fawk. I am exactly the guy that needs a damn step-by-step instructional from someone with a clue.

The liquified foam reacts with the adhesive and makes it very slick. I found that duct tape didn't adhere strongly enough to the bottom of the car to prevent the stuff from pushing through and allowed it to effectively peel off the tape from the inside. Both gaffer tape and gorilla tape (when I ran out of gaffer tape) seemed to do a better job of keeping the bottom sealed.

Awesome info.

Now to go buy gaffers or Gorilla tape. I'll probably give the metal/paint a rub-down with some alcohol/solvent to make sure the tape can stick really well. Sal will know what to use. He'll probably let me help him do some taping or prep work, while I also shoot pix.

Update:

All sample/test product ordered/paid-for. Gorilla tape purchased.

Stopped by and talked to Sal. He has been watching YouTube videos (two of them, I think) on foam-sealing an S14 chassis. I'll see if I can get him to post a couple of links for us.

Should be Tuesday that I can deliver both foam products to Sal. Then we can mess with the product, and shoot pix. See what's up on how the two (2) types of foam work, filling spaces, and expanding. And we'll do that before we touch my vehicles chassis.

I'm excited.

Brennan didn't seem to have any trouble. He just let it expand and trimmed it off:

http://www.sr20-forum.com/79520-post107.html

That's actually a slightly different kind of foaming. More specifically, it's a different kind of foam. Great Stuff is a highly aerated, quick cure foam that's great for stopping heat and damping noise. It's not so good for structural purposes though.

Not to say that Brennan did anything wrong. I think Brennan made the right choice of materials there. I'm just not sure if it'll work for what Shawn B is looking to do.