Firewall Mounting Options

[Brian74]

Did anyone else use something other than rivets? Contemplating stainless rivnuts as I like the ability to remove stuff later on if need be.

Any better ideas?

 

[Mayor West]

Self-tapping screws? I used those instead of rivets on my tunnel cap because riveting that just seemed like a future headache.

 

[Ross]

I have had better luck with riv-nuts than I have with self tapping screws.
The self tappers that I used eventually rusted, and worked their way out.

 

[Desert Sasqwatch]

If you would like to be able to remove and reinstall and not have issues the riv-nuts with button head screws are the way to go.

 

[Brian74]

I guess rivnuts it is. I’ll probably back the firewall with neoprene as well to eliminate any potential buzz or vibration.

 

[Fozda]

I've heard of people putting some loctite on the shank of the rivnut when installing them to help ensure they don't start spinning on you when trying to remove the bolts in the future.

 

[Brett]

I picked up an aluminum rivnut setup off the internet for cheap. It seemed to work well and didnt require a bunch of working space. I did my tunnel cap and naca ducts.

Amazon.com: Speder 136pcs Rivet Nut Tool Kit Rivnut Tool Blind Nut Rivet Gun kit Wrench Threaded Insert Rivnut Nutsert M6/ M3/M4/M5/M8 Set for Furniture,Decration,Car,Trailer,Boat,and More: Home Improvement

Amazon.com: Speder 136pcs Rivet Nut Tool Kit Rivnut Tool Blind Nut Rivet Gun kit Wrench Threaded Insert Rivnut Nutsert M6/ M3/M4/M5/M8 Set for Furniture,Decration,Car,Trailer,Boat,and More: Home Improvement

smile.amazon.com

I would not use this for significant load bearing items.

 

[Brian74]

I picked up an aluminum rivnut setup off the internet for cheap. It seemed to work well and didnt require a bunch of working space. I did my tunnel cap and naca ducts.

Amazon.com: Speder 136pcs Rivet Nut Tool Kit Rivnut Tool Blind Nut Rivet Gun kit Wrench Threaded Insert Rivnut Nutsert M6/ M3/M4/M5/M8 Set for Furniture,Decration,Car,Trailer,Boat,and More: Home Improvement

Amazon.com: Speder 136pcs Rivet Nut Tool Kit Rivnut Tool Blind Nut Rivet Gun kit Wrench Threaded Insert Rivnut Nutsert M6/ M3/M4/M5/M8 Set for Furniture,Decration,Car,Trailer,Boat,and More: Home Improvement

smile.amazon.com

I would not use this for significant load bearing items.

You aren’t worried about galvanic corrosion?

 

[Desert Sasqwatch]

I purchased the steel rivnuts to avoid the corrosion potential. When installed correctly they are strong attachments for body panels and other non-load bearing items. As long as they are not 'torqued' the rivnuts will stay put and not rotate. Please note the radiator mount from DF is rivnuts and works very well for mounting a load bearing piece.

 

[Brian74]

I purchased the steel rivnuts to avoid the corrosion potential. When installed correctly they are strong attachments for body panels and other non-load bearing items. As long as they are not 'torqued' the rivnuts will stay put and not rotate. Please note the radiator mount from DF is rivnuts and works very well for mounting a load bearing piece.

I’ve got a couple of rivnut guns. I have stainless rivnuts I bought for aluminum but I’m hesitant to trust those for fully blind holes as stainless reputation for galling. I’ll try and find some nice quality zinc coated ones.

What size will you end up using on the firewall?

 

[Desert Sasqwatch]

I was looking at using M4 button heads for all of the body panels. Seems to be the right size visually and the M4 screws fit without redrilling the holes in the body panels.

 

[Brian74]

I was looking at using M4 button heads for all of the body panels. Seems to be the right size visually and the M4 screws fit without redrilling the holes in the body panels.

I didn’t want to have to enlarge the holes either. Only problem I’ve had is with the smaller steel rivnuts, is these cheap Chinese mandrels don’t get a good enough bite on the threads and end up pulling right through the rivnut. 3MM pictured.

 

[Desert Sasqwatch]

Yep, I've had that happen also. Mandrels are pretty cheap to replace though.

 

[SmsDetroit]

I’ve been look at riv-nuts for the side panels and firewall. From what I’m reading it sounds like 4mm should be used. Is that correct? It also sounds like using them for the floor pan is not a good idea.

 

[Brian74]

I’ve been look at riv-nuts for the side panels and firewall. From what I’m reading it sounds like 4mm should be used. Is that correct? It also sounds like using them for the floor pan is not a good idea.

I decided to go with 4mm zinc plated steel rivnuts. Holes need to be enlarged just slightly which should be optimal size for them.

 

[Brett]

You aren’t worried about galvanic corrosion?

Not really. If it happens, then I drill them out and do it again.

Edit to add that I will be rebuilding so I will have the chance to switch if it is a real concern for the 8 spots I used them on the tunnel cap.

 

[ccannx]

The upper control arms on the front of the c5 and c6 corvette are bolted into rivetnuts in the frame. We popped one out by accident and tack welded the new one just to make sure it wouldn't slip.

 

[Brian74]

The upper control arms on the front of the c5 and c6 corvette are bolted into rivets in the frame. We popped one out by accident and tack welded the new one just to make sure it wouldn't slip.

For the light duty of the firewall fasteners, I think a small drop of blue loctite and a careful effort when uninstalling will be sufficient.