What is the big difference from making the seat between these two options. I know one is 40 dollars vs about 200. Is it just easier? I never have made either.
Bead seat vs the foam seat
What is the big difference from making the seat between these two options. I know one is 40 dollars vs about 200. Is it just easier? I never have made either.
Bead seat provides significant impact protection in the event of an impact going backwards say into a guard rail. IRL, Champ Car mandate the use of it so that speaks volumes for it.
foam costs $40 and provides very very little impact protection.
The processes to make one or the other are a bit different but neither one is terribly difficult.
Richard Pare has some ideas on how to get the impact protection for lot fewer $.
I think he will probably weigh in on this one.
CHeck with John Goss at Pennon. www.pennon.com
Short story: The foam seat can make a BIG mess, and requires a bucket, two measuring cups, a wire hanger, and several garbage bags -- all of which will be thrown away afterwards. It's a decent option for someone who will drive the car once, OR for figuring out what size beaded seat kit you need.
The bead kits can make a mess if you spill the beads (unlikely), but only require a shop vac and a marking pen. Pretty much everything else is included in the kit.
I've done several foam seats and just one bead seat. Not including curing time, the bead seat took one hour, start to finish, with one helper. The foam seats have taken from two to six hours (with two helpers) -- set-up, clean-up, oops this pour wasn't enough gotta do another...
I can send instructions for both via email if you want to compare the actual process.
I've done both foam and bead seats. The bead seats are much easier.
One hint: Some bead seat kits don't come with a valve on the fitting where you attach the shop vac. Go to Home Depot and get a 2 dollar, plastic on/off water valve that matches the size of the fitting. This will allow you to put a partial vacuum on the seat when prefitting the driver in the car ( before adding the resin ). And allow you to turn off the noisy shop vac while the driver is sitting in the final resin mix.
Bill Hetzel
The cheapest way to make a bead seat is by building it up using styrofoam boards. You can get 2' x 4' x 2" boards thru McMaster-Carr, or quite often from places like Home Depot.
You will need a bandsaw, an extremely sharp knife, a belt sander, a 3" right angle disk sander, and spray-type contact cement. The use of these utensils will proceed to make a hellatious mess in your shop, so a very good vacuum cleaner will be indispensible!
The proceedure is easy: just cut, glue, and sand until you have the exact shape you want. The areas to be glued will want to fit against each other as closely as possible to form a good joint with minimal gaps.
Once the shaping is done, coat the seat with a layer of epoxy resin, and cover the backsides with a layer of glass cloth. After the resin is hard, you can glue on any covering material you want to use.
the crossle is finished - made a foam seat in under two hours start to finish the other night - two friends and self in car to do the pour - had half a can of the two sitting on the shelf so why not use it up? i think the key to avoiding a big mess is use lots of cardboard on the sides to avoid chassis intrusion and up behind you to avoid the mess of the foam getting on important things - the local auto upholestry shop covers them for me, often with a scrap piece so it's dirt cheap and it looks great- just for the learning experience, i might make a bead seat next time - then i can really answer your Q, but i'm willing to bet the others in here that say a bead seat is safer on rearwards impact are correct. gives one something to contemplate - after the pelvis/arm fractures i bot a HANS - so since i'm on a bit of a safety campaign these days, this thread may motivate me about the seat too.
I'm doing the R. Pare version this week and am going to make the Indy/F1 type side protectors as well. With this method it will be easy to shape them around the upper tube and tape them in place after belting in.
Bead Seat Alt
Quote "I'm doing the R. Pare version this week".
Pls report back - method seems too good to be true - second opinion would be appreciated!
I would like to re-do my seat this winter and have thought about the Mr. Pare version, I think it has been described before. I think it offers more opportunity to get a nice tight fit to the chassis plus some leway in correcting any mistakes. Currently have a bead seat, but am not quite happy with my position, plus after 4 seasons it is starting to fatigue in a few spots. I am wondering how the crash energy absorption of the store bought foam sheets compares to the foam in the bead seat kits? I know we don't have to worry about 100g hits into concrete walls. Is the epoxy/fiberglass layering over top one of the keys to making the piece together seat work? Is there a specific grade of fiber cloth recommended for this?
Scott
The glass cloth wants to be used as reinforcement only on the outsides, not on the surfaces your body bears against. I used satin weave for the seats I did, but the regular weave should be ok. The cloth used to make it look pretty can be almost anything you want, but I would try to find something that has some fire resistance.
The last seat I made this way was done 5 years ago and still looks brand new.
The energy absorbtion should be just about the same, if not slightly better because of its being more homogenous.
You want the white expanded polystyrene bead boards, not the other blue or pink stuff. The other stuff might work just fine, but I have no info on it so can't recommend it.
I still have a hard time beliving there's real data that supports the position that bead seats are more energy absorbent in this application. Lots of surface area, soft tissues - it's not the same as a helmet.
Believe as you wish. There has been a LOT of testing done by the IRL and CART together, as well as F1, which is why expanded polystyrene bead seats are mandated in those series.
The whole idea in energy absorbtion is to allow an increase in decelleration time by crushing at a controllable rate, without the energy absorbtion material rebounding at or near the end of the impact - the forces generated in the rebound phase will actually increase the g-loading seen by the driver, and can be lethal if high enough.
In the case of a soft-tissue body, the energy absorbing material has to be very homogenous, without any soft or hard spots. The 2-part foam we all used in the past is notorious for both problems. I suppose that if you cast up a solid block and then cut away what you didn't want, THEN you would have a chance of getting a homogenous density throughout the seat.
I'm not quite getting the idea behind the Pare seat.Seems like a LOT more work than a bead seat. Could someone post a picture or two of a completed seat? Or even better, progress photos...
Thanks
Steve
Fellas;
I'm going with Richard's concept. Seems like a clever way to get a precise fit to a removable seat as well as side panels.
I tried McMaster-Carr for 2' x 4' x 2" expanded polystyrene bead boards, but no luck. Any recommendations as to where to buy EPB in those dimensions?
Next, adhesive recommendations?
Iverson
V/r
Iverson
board
I got an 8'x2'x2" piece yesterday at Home Depot in Vancouver for 10 bucks, cut in half to fit in the car. They had lots of different sizes. All purpose construction glue in a squeeze tube was 5 bucks. Just a little bit cheaper than the bead kits! I got a board that is very lightly impregnated with the same type of green resin that is in those bead kits. They also had plain white styrofoam, but this looked a little more stable. I will assemble the tools, have to borrow a belt sander, and start this week.
Richard - my point was that the bead seat companies don't supply any engineering data to go with their claims. At least the neck restraint guys have a standard. The initial thoughts on these were if it works for your head it must be OK for the rest of you.
I think the important thing about a seat is not to provide a fulcrum for your hard parts to bend over (something my current stock VD seat is really bad about).
Would be interesting to compare measured racing crash G-loads and duration to common household/industrial accident loads - like falling off a roof.
Steve:
Yes, it can be a lot more work than the seat kit, both in the making of it, and the cleanup afterwards. The nice thing about it is that you cannot possibly screw up the fit - lord knows how many seats I've done that the driver decided he didn't like and were thrown away shortly afterwards! This is the real reason I recommend this method - I'm just as capable of screwing something up as the next guy!
If you can get the bead board locally, instead of having it shipped in, your total material cost should be less than $50.
Proper Expanded Polystyrene Bead board should have no color to it other than the white of the beads - it will look exactly like the styrofoam used for coolers and packaging electronics.
I'd be careful about the use of some of the available construction glues in tubes. While they will glue it together, they also usually harden up to something a lot less flexible than we want the crush into. They usually also take a lot longer to get to the handling point, and I don't know about you, but I don't really like waiting hours for each joint to dry enough to start working the piece again! The spray contact cement (3M 777 work great) sets up quickly and doesn't produce hard spots.
Rick I:
The McMaster-Carr part # is 9335K3 for a 24x48x2" sheet (page 3257 in Catalogue #111) They come as a 3-pack for $30. The killer can be the shipping - the first time I bought some I think the shipping was about $65 - for some reason they sent it by truck, not UPS.
Last edited by R. Pare; 11.06.05 at 1:34 PM.
They don't need to - the sanctioning bodies did all the work for them!Originally Posted by Rick Kirchner
At one time, quite a few years back, Racecar Engineering published the data from some of the first tests - I remember specificly the F1 head surround crash test data done on a Mclaren, and an article on a "safety seat" being tested using differing materials for different parts of the body (the gist being that a knee has different requirements than the torso, etc, and in it was the data from some sled tests. I believe also that you can request the data from CART and the IRL.
Please any doubters, remember that the Expanded Polystyrene is essentially what absorbs the impact energy in your brain bucket.
I do not know of a better endorsement than that.
Unless anyone wants to pour some 2 part foam in their helmet and crash test it.
Richard;
Thanks, Bud. Just ordered 2 packs of 3, arriving tomorrow out of Chigago. And at your expense unfortunately, we can all learn the lesson to request a quote for P/H. This order was $6.00.
Iverson
V/r
Iverson
I'm still not there on the Pare seat...
I understand the poured foam and bead seat concept, "stick it in 'n wiggle around" and all the nooks and crannies of the car and my back are filled in. The seat isn't going to move around in the car and I'm not going to move around in the seat.
Is the Pare seat like building the seat out of Lego? You know, put this block here and that block there and ultimately you have a seat? Do you start carving and sanding once you get the basic shape right? I can see spending many an hour just on getting the lower back comfy...
Again a picture may be worth a thousand words.
Richard, sorry for not "getting the idea" with this quicker. Really, I can design and build a computer from scratch, but a simple foam seat...
Steve
Bead Seats
I'm still trying to get this whole thing right in my mind. I am trainable. I'm doing this in a Lola T-342. Do I put the foam board on the sides to keep everythging from running out? Do I then leave the foam boards in place? What if I use cardboard? It seems like there is a lot of room for movement. Having raced a Mini before I did not have this problem with a ridge seat. I just don't want to end up being "spam in the can" if something bad happens. Since the car now has a fuel cell in the back the amount of room has also changed. I want to get as low in the car as I can. I am 6 feet tall at last count. Do I end up using mouse pads to sit on?
MIke
more details please
I have a couple of additional questions about the design of the seat and the support of the seat.
What is the minimum "safe" thickness that is safe for the "back area" in a rear impact? Is one inch of bead foam thickness enough if you back into something hard? Is it better to have a small thickness of foam or a large thickness of foam in the "back area" for a rear crash and forward of the "butt area" for a forward crash?
If the seat belts allow you to move forward 3" in a heavy frontal crash and the front of the frame is just a little forward of your feet , it is important to get the frontal crash protection just right. There is not enough room for the belts to do all the work.
How much of a front bulkhead is required for the foam to rest against for a front impact ?
Should we have a bulkhead/seat panel that goes 2/3 of the way from the butt to the knee to form a structual panel and then cover it with foam? Should that same panel be vertical to stop the "ramp" effect in a frontal crash or should it be at the same slope as your thighs when you are in the car?
6'3" in good health and wantting to stay that way
aka "newbie formula guy"
DLM
Steve,
You have the Pare seat concept right on the money.
Take the sheets and start whittling til they fit you properly (comfortable) and glue em together.
The advantages are that the cost is a whole bunck less, if you mess up some part you don't have to buy another bead seat kit, just recarve that particular oiece and it should not take a whole lot longet than properly "pouring" and trimming a bead seat.
The only minus that I can see is that is gonna be a bit messy.
Steve
Guys I think Pare is talking about sculpting a seat from layers of the styrofoam... same way an artist makes a statue from a piece of marble. Keep cutting away until the first layer is right, glue on another layer and repeat. If the 1st block was say 2" thick I would 1st shape it to fit into the car and perhaps start sanding out where my butt goes. Then the next layer which would be mostly behind you, and so on.
Sean O'Connell
1996 RF96 FC
1996 RF96 FB
2004 Mygale SJ04 Zetec
Seat
I have a steel tube with aluminum panel seat back in my car that I made to replace the glass seat. I also made a "butt catcher" on the floor. Now I am going to probably use the liquid foam stuff to snug myself in and fill in the gaps, . I never heard of relying on foam for a seat in a racing car. If that foam breaks, the belts are going to go to full loose and my back would probably be broken by the fuel cell bulkhead.
I would think the back of the seat in an indy or irl car is fully supported by the tub, as are the sides. In my Lola, the chassis is at maybe chest level and the back support of the fuel cell ends at mid-back. I don't think foam is intended as a replacement for a "seat". If it is there must be some parameters around this.
If you are comfortable with the foam, that is fine. I can't believe it is right for every car.
The foam is not intended to be used for structure - it obviously isn't strong enough for that. It is meant only to be the padding that cushions your torso. It has to be fully supported by interior panels.
If your car does not have interior panels that cover over the frame rails and fuel cell, then you need to put some in. If you have no frame side braces that would support the interior panel beside your torso and hips in a lateral impact, you really need to add some. The last thing you want is for your body to be able to punch the interior panel through big gaps in its support structure. You also want lateral support panels for your shoulders.
What is the recommended material and thickness for an interior panel?
What is the recommended method of attaching said interior panels to the frame rails?
Anyone have pictures of their cockpit they can post?
Fellas;
Anyone know of a vendor that carries bolts of quilted, tripple layer nomex in a variety of colors. I'm trying to contact Simpson for purchase price per sq. yard.
Iverson
V/r
Iverson
you can buy fire retardent materials in bulk from the Bell/Pyrotect guys in Sun Valley, CA.
1-800-669-BELL(2355)
Watch using 3M 77 on EPS foams. They changed the formula and it now contains acetone, which melts the foam. The modeal airplane guys found this out the hard way.
Ther eis a spray glue for foam from 3M. 3020 IIR. You can get it at craft stores. Michael's carries it, in teh foam section (not inteh glue section).
Ding, ding, ding...
I get it now, first thing I need to do is build an aluminium "box" to contain the foam (and me). I knew there was something simple I was missing.
Thanks
Steve
Bead seat.
A well made bead seat is made to partialy wrap around some of the frame tubes of a chassis.That helps locate the bead seat and spread any impact loads. The finished seat is cut into 3 or 4 interlocking pieces to make it removable. I watched a local expert named Troy Stevens make one for a fellow racer and it was a work of art when finished!I just visited Doug Brenner last weekend and he had Troy make a seat for him that is incredible! I hope Doug can post some pic's of the finished product here as his car has the body work removed and you can see how a proper bead seat is made. We were in his shop on Sunday when the CSR race (Runnoffs) was on TV and he climbed into his race car to watch! Jeez why not it was the most comfortable seat he will ever have!
Still waiting for recent 'newcomers' to report on how they got on with the Pare seat method - Brad? - Rick? - any experiences to report?
One question I have - which diretcion do you lay the 2"/4" slabs? - horizontal? - vertical/longitudional? - vertical/lateral? or sloping-same-as-tub-back?
Thx - Derek
[QUOTE=D.T. Benner]I just visited Doug Brenner last weekend and he had Troy make a seat for him that is incredible! I hope Doug can post some pic's of the finished product here as his car has the body work removed and you can see how a proper bead seat is made.
Here are some pictures of how my seat fits around the frame tubes. Here is a link to Troy Steven's (maker of the seat) website. http://www.racecarseat.com/ This seat took two days to make and is a functional work of art..........
www.brennerfabrication.com
Last edited by Douglas Brenner; 01.16.07 at 5:23 PM.
Seat
It seems so strange to see so much foam and no support. I would think you would have all the seat in an aluminum tub. Unless that is stronger than I expect foam to be.
That seat as it sits right now is about as dangerous as you can get!
At a minimum, you need very well attached panels on the outside of the tubes to captivate the seat in a lateral hit. Even then, if the panels are not attached strongly enough the panel taking the load will just rip away. All that will happen right now is that the drivers weight will crush the seat at the tubes and give him a big impact at the tube when the foam no longer has any crushing left.
To make a seat be effective, it needs to be totally captivated by well supported panels that are on the insides of the tubes.
Throw that thing away and start over!
[QUOTE=R. Pare]The foam is not intended to be used for structure - it obviously isn't strong enough for that. It is meant only to be the padding that cushions your torso. It has to be fully supported by interior panels.
[QUOTE=R. Pare]The foam is not intended to be used for structure - it obviously isn't strong enough for that. It is meant only to be the padding that cushions your torso. It has to be fully supported by interior panels.
Gee, I was just trying to help out. This seat is NOT foam ! Is is a properly made bead and resin seat. It is strong and thick where it counts, much stronger and impact absorbant than a sheet of .063 aluminum, pop rivits and some two pound foam from Home Depot. If you saw the seat up close you wouldn't be so critical. If this seat fails, I am a goner anyway................Also, there is kevlar in the side bodywork and sidepods after that. Each to his own I guess............Next time I will just stay out of it.
www.brennerfabrication.com
Last edited by Douglas Brenner; 11.16.05 at 6:05 PM.
Doug:
Regardless of whether the seat is made of 2-part foam or of beads, if the sides are not fully supported by panels, be they interior or exterior, it will point crush in a side impact along the tubes it is wrapped around. Just your normal loads in the car while racing it will fret and crush away the places that it is hard against the tubes.
If the beads are encased on the outer sides in a hard, and thick, shell of glass and resin, then it has a chance of lasting thru such an impact and performing its intended function.
IF the exterior side panels can withstand a 30g or higher load bearing against them from the inside, then you are fine. If not, they will just move out of the way and the beads will proceed to crush along the tubes.
Been there, seen it happen.
Just trying to make sure you are aware of the possible consequences. I hate to see guys get hurt!
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