bonding of stressed-skin

[gr3pz]

in formula sae, what are the methods of bonding stressed-skins to steel tube (the chassis)?

[gr3pz]

in formula sae, what are the methods of bonding stressed-skins to steel tube (the chassis)?

[Travis Garrison]

Zip-ties

[BryanH]

Get real. Sikaflex is the go!

[alfordda]

We use Elmers glue, but I'd use the search function to find out what 3M or Hysol stuff everyone else is using. That is unless you want to glue it back on every 10 minutes.

[Lyn Labahn UW-Madison]

Cherry Q rivets and Loctite E-120HP.

[RickyRacer]

There is an article on bonding in the new issue of race car engineering. You might want to pick it up. I have it but haven't had a chance to read it yet so that is where I will leave you.
Ricky Torres
Long Beach State

[Gumby]

we use 3M's DP-460. you can check out what we did at our web site (http://www.ryerson.ca)

Adam

[gr3pz]

In formula sae, the skin has to be impermanent and removable from the frame isn't it? so I reckon bolt and nut or zip-ties, but using the bolt and nut will reduce the frame rigidity. I never know how to use zip-ties. Is it by drilling the skin and tied it up to the frame?

[Greg H]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by gr3pz:
In formula sae, the skin has to be impermanent and removable from the frame isn't it? </div></BLOCKQUOTE>
I don't know where you read that from but it isn't true.

[Travis Garrison]

gr3pz,

I was just being an ass with the zip-tie comment...

Lyn Labahn gave you a really good answer with the rivets (mainly at corners or in the middle of long edges to reduce peel) and loctite...

Unless you need to get at something behind the skin bond them on.

-Travis

[gr3pz]

Actually zip-tied is a good idea. It's cheap, we can easily take the body off and on from the frame, the products are easy to find, and it don't have anything to do with the frame rigidity.

If we using adhesive bond such as glue, it will be difficult to release the skin. (It's only my opinion)

Using fastener such as bolt and nut or rivet will make the frame less rigid and ultimately will reduce the frame strength, because if we using fastener we need to drilled a hole into both the frame and skin.

What do you guys reckon? Will the torsional force from the frame undergo the zip-tied bond of the skin?

-gr3pz-

[Rob Davies]

How do people go about bonding their skins if they want their chassis to be powdercoated. If its bonded before the powdercoat the bonding resin will be taken above its reccomended temp wont it? Then if the bonding is done afterwards we will be bonding to paint which I imagine wont be as good. Im thinking of getting the chassis painted first and just masking areas where the bonder will go.

Any thoughts??

[gr3pz]

is there any other method for bonding the skin to spaceframe beside using glue?

[carts]

Hey guys,

We did a few tests last year when we were going to bond on the floor pan which was aluminium honeycomb sandwich panel. We did shear, peel and tensile tests on plain CR4130 and powdercoated 4130 and as long as the surface prep is good there is not a significant difference in the bond strength..

[Rob Davies]

Carts,

Thanks for the info. Am i right in thinking when you say powdercoated that meant bonding to the powdercoated steel. I think so but not sure.

If so ill just get the chassis painted and then bond.

Thanks, Rob

[Daves]

We used methacrylate to bond the carbon fiber to bare steel tubes.

[carts]

Rob,

Spot on, we bonded straight on to the powder coated surface.. We didnt test it with normal paint so i a cant comment on how well that would take?..

[gr3pz]

the chassis surface coating wont be a problem if we bond the skin to chassis using fastener. (for example bolt and nut)

we just need to put some kinda rubber between bolt to skin surface and chassis surface to nut.

-gr3pz-