Stiffen the unibody with polyurethane?

donk_316 · Post by **donk_316** » Sun Jul 23, 2006 7:54 pm

http://www.junauto.co.jp/products/reinf ... ex.html?en

Is there a normal verison of thos? can i buy it at home depot? haha! shh! maken drinks with alchohol! lmao! woo!

Shaun41178(2) · Post by **Shaun41178(2)** » Sun Jul 23, 2006 7:56 pm

I couldn't read that shit. Lost in translation anyone?

I think the only good way to stiffen a unibody is to weld the seems.

donk_316 · Post by **donk_316** » Sun Jul 23, 2006 7:58 pm

it sayd verry clearly

"
It is said that a too hard body is not good. A reason is for a maker to perform shock absorption considered for safety.
A body will transmit various information to each part, if rigidity improves. But if body reinforcement is actually performed, wages will become a large sum for reinforcing roll bar spot increase, reliance board reinforcement, etc.
Also it is difficult to imagine what effect it induces. Then, the epoch-making body reinforcement item which can be felt at low cost was developed.
This new reinforcement method makes high rigidity feel simply, so that it reverses old common sense. The car which performed urethane body reinforcement can feel the difference, when it get in and departs, you feel a motion of a car. The car which has constructed the roll cage etc. is still more effective. Although there is a difference in the ratio of an effect also by the new car or the old vehicle, rigidity is raised certainly."

duh!

donk_316 · Post by **donk_316** » Sun Jul 23, 2006 7:58 pm

all your bases are belong to us!

p8ntman442 · Post by **p8ntman442** » Sun Jul 23, 2006 8:32 pm

In my best warren G Voice. Moderators, MOUNT UP!

donk_316 · Post by **donk_316** » Sun Jul 23, 2006 8:36 pm

you gotta problem wid my japan spec chassis stiffener... speaking of asians stiffeners... you should SEE the whores in bangkok... wow!

Kohburn · Post by **Kohburn** » Mon Jul 24, 2006 10:02 am

didn't Will say that he used the spray foam from home depot in his frame rails..

it makes sense to me to fill the roll cage tubing with 2part expanding closed cell foam.. add minimal weight but a lot of additional crush resistance and vibration deadening

The Dark Side of Will · Mon Jul 24, 2006 5:04 pm

Roll cage tubing is so thick that foam filling won't really matter.

The stuff they sell at HDR (Home Depot Racing) is so light that it won't significantly affect chassis stiffness. You need a much higher density of foam to have any effect on chassis stiffness.

rube · Post by **rube** » Tue Jul 25, 2006 6:48 am

lFor foams try:

http://www.smoothon.com/foams.htm
http://www.wicksaircraft.com/catalog/pr ... /index.htm

Kohburn · Post by **Kohburn** » Tue Jul 25, 2006 7:47 am

The Dark Side of Will wrote:Roll cage tubing is so thick that foam filling won't really matter.

The stuff they sell at HDR (Home Depot Racing) is so light that it won't significantly affect chassis stiffness. You need a much higher density of foam to have any effect on chassis stiffness.

the stuff at home depot requires air to cure also - so i don't even trust it inside an enclosed tube

The Dark Side of Will · Tue Jul 25, 2006 11:29 am

It cures inside a big lump of itself.

Pyrthian · Post by **Pyrthian** » Tue Jul 25, 2006 11:52 am

Kohburn wrote:didn't Will say that he used the spray foam from home depot in his frame rails..

ya dont want to fill something that may rust with this stuff. it WILL trap humidity & make it rot faster. it will not seal out water. but, if its well painted/protected (which is HARD to do inside of tubes & box rail) it will keep work OK, and keep dirt out & do some sound deadening.

also, hot spots from exhaust will make large bubbles which will trap humidity. this is NOT something you want to do to your engine cradle without LOTSA pre-cleaing/painting. maybe after a acid dip & enamel dip.

The Dark Side of Will · Tue Jul 25, 2006 11:58 am

The 3M products are CLOSED CELL foam. They don't trap anything but whatever it is that makes them foam in the first place.

Pyrthian · Post by **Pyrthian** » Tue Jul 25, 2006 12:07 pm

the cells themselves, yes
but, there are always gaps. I am not saying the stuff itself soaks water like a sponge. I am saying its more like a sheet of plastic on laying concrete. after its left there a few days, when you lift it up, its damp underneath. there will be air pockets and there will be expansion/compression. the insides of the box rail wont be able to dry out like if they were open air.
also, I dunno the heat resitance, but I expect the stuff will collapse near any exhaust.
but again, if painted/protected, it'll be fine

Kohburn · Post by **Kohburn** » Tue Jul 25, 2006 12:09 pm

The Dark Side of Will wrote:It cures inside a big lump of itself.

when I cut large lumps open i found the inner most air pockets to be very oversized and extremely soft - they also took several days to cure vs the outside that took hours

2-part expanding foam is seriously superior to the cans you get from home depot

you can get small quantities of 2part spray foam (mixes in the tip) from mcmaster

DreX · Post by **DreX** » Thu Jul 27, 2006 5:04 pm

Some time ago I read in a magazine a way to stiff the chasis with a foam. Dont remember the brand tho. Anyway, I was thinking to do something like that for a long time now. Will be good to see where this topic ends.

Good job, keep the brain cells on guys.

DreX

The Dark Side of Will · Thu Aug 31, 2006 9:08 pm

Kohburn wrote:
The Dark Side of Will wrote:It cures inside a big lump of itself.
when I cut large lumps open i found the inner most air pockets to be very oversized and extremely soft - they also took several days to cure vs the outside that took hours

2-part expanding foam is seriously superior to the cans you get from home depot

you can get small quantities of 2part spray foam (mixes in the tip) from mcmaster

What page, or what product?

stimpy · Post by **stimpy** » Thu Aug 31, 2006 10:13 pm

The Ford Truck "Quiet Steel" is essentially this stuff.

donk_316 · Post by **donk_316** » Sat Sep 23, 2006 7:57 pm

Any one figure out what this stuff is? I pulled my door sills and there is foam inside them already

Kohburn · Post by **Kohburn** » Thu Mar 15, 2007 7:40 am

just requires a 2part expanding foam rather than a 1part like the foam cans at home depot. I now have an expanding foam mixer for spraying insulation, could easily spray it inside a frame rail.

I can get closed cell foam in densities from 1.7 lb per cubic foot to 3 lb per cubic foot.

the 1.7# is strong enough to walk on - the 3# is rated for use as a roofing material it is so hard.

you can get small amounts of 1.7-2# foam from little kits like...

http://loyola-1.stores.yahoo.net/frpk180.html

can get 3# from here

http://www.intechequip.com/frothpak.htm

these kits don't need any additional in order to use, they come with hose and nozzles.