How to attach stuff?

[Bill in Houston]

How can I attach my aero stuff in ways that won't require making permanent cuts/holes in my sheet metal? I have used a couple of methods, but I figure you guys know of others.

The ones I have used:
1- foldover or speed nuts
2- push rivets (trim fasteners)

The underside of my car has dozens of holes in it, just waiting to have a belly pan attached. BUT, I can't get to the backside of most of them, if you know what I mean. I only have access from the outside of the hole.

Any ideas that you have are welcome!

[trebuchet03]

I'm researching non permanent adhesives.... My final exams are coming up so I haven't had much time to fool around with it. But I was looking at some sort of hot glue adhesive to attach snaps.

I'm also looking at applying the adhesive to the window glass to prevent any uneven UV damage

At least - that handles modifications top side.

As for the bottom, I think I'm going to go with 3M dual lock. It's like velcro, except it's hold is much stronger - I've heard it called knuckle velcro because of how it bonds. Both sides are hard (unlike velcro hook and loop) and they "smush" together. It's a pretty cool non permanent and strong fastener

Large yachts use it to hold up their headliners (they are removable). And I've seen people hanging from the ceiling holding on to these headliner panels attached with this stuff. You have to release a corner and slowly separate the two halves

[northboundtrain]

I would guess that good any adhesive will still scar/peel the paint when you try to remove. a screw hole is fairly easy to patch. Either way, if repainting the panel is going to be necessary then that is the big expense.

[Peakster]

I was actually at one point thinking of using strong rare-earth magnets to attach wheel skirts, boat tails, etc. I'm certain they would work real well, but they cost $2.50 a pop in the Art Store on campus.

Attachment 371

[tor07]

I've got the same problem, but I think I have a solution. The holes in my chassis are fairly large, 3/4" and up. The largest push rivet I've been able find is 1/2" after looking and talking to local suppliers. So after all that work, and after a trip to the auto parts store, I found a expanding rubber plug that goes on radiators. It comes in a fairly wide range of sizes. It has a slight lip on the metal end that crushes the rubber that I think will be able to hold the choroplast up. If not I should be able to put a washer on it and still make it work. I also don't want to drill and tap holes in my chassis. I've thought of filling hole and drilling them to except the push rivets.

Anyways, hope this helps and I hope someone else has another idea.

[brucepick]

Yeah - the rubberj plugs are called well nuts.
Different sizes and screw thread sizes.
You get them in the fasteners section at hdw. store or big box store like Home Depot/Lowe's.

They have another name too but I can't recall right now. Expansion plug?? They're a lot like an expansion fastener like a Molly for wallboard, just made of rubber.
Volvo roof racks are held on with them.

[trebuchet03]

Originally Posted by northboundtrain

I would guess that good any adhesive will still scar/peel the paint when you try to remove. a screw hole is fairly easy to patch. Either way, if repainting the panel is going to be necessary then that is the big expense.

Define "good" :P Good is based on application - I'm not looking to hold heavy beam - perhaps a few pounds distributed over a large surface area I've found one adhesive - the same stuff that is used on dent pullers (the type that uses glue on bits). I'm gonna ask at the marine shop at a ship yard and see what they come up with But no worries - they said the same thing about post-it notes just before they were released :P

I was actually at one point thinking of using strong rare-earth magnets to attach wheel skirts, boat tails, etc. I'm certain they would work real well, but they cost $2.50 a pop in the Art Store on campus.

Here's how I sourced my Rare earth magnets for cheap

My concern is... a gust of wind will get under there - even slightly -- pull up a few of them and then it becomes a domino effect. One solution could be to have the thin roll type magnet on the leading edge to "seal" out any big gusts

[Bill in Houston]

Great ideas so far.

The other name for those rubber expanding plugs is "freeze plugs" but that is not the official name. It's "expansion plugs" or something like that. I had thought of them before but had forgotten. Those would be great. Thanks for reminding me TOR07.

One thing that I am trying to keep in mind that may apply to you, Trebuchet, is that the wind blows from pretty much just one direction. The front edge can just be a hook or something that is strong in only one direction, and then the rear edge does the job of holding things up and in place. So for a belly pan, the front edge hooks onto/into something, and then the edges and rear are secured with magnets, omnitape, etc. The positive action of the hook keeps air, vibration, whatever, from getting in there and starting the domino effect.

Great stuff. Keep the ideas coming...

[trebuchet03]

Originally Posted by Bill in Houston

So for a belly pan, the front edge hooks onto/into something, and then the edges and rear are secured with magnets, omnitape, etc. The positive action of the hook keeps air, vibration, whatever, from getting in there and starting the domino effect.

Very good point :P I guess I'm not thinking that way because I'm in boat tail mode But ya, that makes complete sense :P