homemade bead seat

[heapcoup]

I am thinking of making my own bead seat using two-part polyurethane foam and bean-bag refill beads. Will this work? What do the commercial bead seats use for beads? My concern is that the polystyrene might react with the polyurethane and I would waste all that foam.
Has anyone ever done this before?

[Tim FF19]

Mixing everything together might be a problem. I don't think you will have time to mix it and then pour it in. Once the foam starts to expand its too late to pour. You could just buy some epoxy resin instead (polyester will disolve the beads) and don't forget the bag with a vacuum port. Then you would have a real bead seat. Buying a kit may be the most economical by the time you are finished.

[JHaydon]

Yeah, what Tim said.

The kit makers have already designed the bag, calculated the beads-to-glue ratio, and formulated the glue to be compatible with the beads.

When I did an Indy-Seat this spring, I found that they had made the whole project very easy. They had even included a mixing bowl so I didn't have to use one of my own.

[ckuhtz]

Got any recommendations for suitable kits?

[JHaydon]

The kit I used was one of the Indy-Seat kits we sell (I tried the 40 liter, 44x58 bag size, and it was only a little more than I needed -- our part #404458). I'm a small guy, so I needed to be moved forward and up, with a little padding on the sides. This size bag extended far enough to support me everywhere, and I cut off a little of the length after it was done.

I found the kit to have very good instructions (as with anything, read them through before starting -- my helper hadn't, and I had to talk him through it) and I only needed to add a mixing stick, a shop vac, a car, and a helper. We got it done in about an hour. I covered it with headliner material from a fabric store using Elmer's spray adhesive.

I've heard good things about the Pennon seat as well, but I haven't tried one.

[Daryl DeArman]

Harry,

The two part foam kit expansion will be an issue (re:mess), not sure chemically how it will blend (your main concern). You could always try the smallest batch where you can accurately measure the proportions and do your own experiment.

If you do source your own two part epoxy and beads, get epoxy that is NOT CLEAR. It will be much easier to make sure you have an even coating on the beads when you mix it. You want as thin and as even coat on the beads as possible. Make sure the epoxy is also compatible with the bag you pour it in! Use a non-opaque bag so that you can see your bead/epoxy mixture. Sure would suck to have the bag fail on you and coat the inside of your car with beads and epoxy.

I used the Pennon kit for my Crossle and will be doing one for my Vee soon. The Pennon kit comes with everything--down to the stir sticks. You need a helper, shop vac and a little patience. If you want what is left of my kit when I am done you can have it. It won't be enough to do another seat but certainly enough to help you source your own materials.

-Daryl

[Rick Kirchner]

My guess is the bag is as much a key component of these kits as the beads and epoxy. Whereas you can just use a real heay garbage bag for pour foam, you have to work the beads around and squirm with the bead kits, which subjects the bags to more wear and tear. The one I had was mylar. I've yet to see a clear polyethelyene bag that was durable - I'm sure they are out there if you do some research.

I'm still having a problem with the claims made as to the safety benefits of bead seats. At impact, unless the epoxy bonds fail allowing the beads to crush down, I don't see any difference between the bead seat and a pour foam seat. The reason is that there's just an enormous amount of surface area, and even under a hard hit the surface loading is pretty low. The stuff works in helmets because the impact surface area is not only much lower, but your skull is a lot harder than your butt, ribcage, and lower back. A 2lb/sq ft pour foam seat ought to be no worse (although I've had a hard time getting a quality seat out of 2lb foam and had to use 4lb stuff.

From an ease of use standpoint, the bead seat appears to be much better, but they certainly aren't very durable in my experience. I'd think peeling off the bag and covering the whole thing with a single layer of 1oz/yd glass on the top and some heavier stuff on the back would do wonders for the durability while not killing the absorbtion properties.

[kbee00]

I used the kit that Pegasus sells and have been very pleased with it - the process is simple and you can't really screw it up. The only thing that I can add is that it is worth the time and trouble to have it covered. Or glue on some decent leather - or whatever. I also believe that the bag is at least as important as the other components - and the kit bags are generally better than you could find on the retail market. But I can also understand the impulse to make it yourself - maybe you can find a better way!

Loren

[heapcoup]

Daryl;
The remnants from your seat will be fine. I use that memory foam for my seat as you know and I like it better than anything. I have mounted the FireCharger in the gap under my knees and I want to cover it with something. I also want to do the same thing with the battery.
my thinking was that polystyrene beads would be an adjunct to the foam and lighten it some.
The bead seats I have seen are all too expensive when compared to the prices of two part foam...if you look around...and I found a 2 gallon kit for $75 plus shipping. That is a lot of foam.
McMaster Carr sells the ComfortFoam in several densities and thicknesses and I recommend it; the stuff really snugs you in. The material is proven to absorb shocks and I think it even dampens vibration from the car.
Thanks for all the advice, gentlemen, my question was answered.
The best deal I have seen on polyurethane foam is from Washington state and the man who took my order did not act like a DMV worker (i.e. nice) He was not fully aware of the many uses of foam in a race car; I will give him my business from now on:

Fiberglass Supply, INC
fiberglasssupply.com
314 West Depot | P. O. Box 345 | Bingen, WA 98605-0345
Phone: (509) 493-3464 | Fax: (509) 493-4053 | E-mail: fiberglass@gorge.net