Metal Washers

General Composites Discussions Composites Talk
#1

Just a question. I’m trying to figure out the best way to attach a cosmetic piece with damaging it the least amount possible just encase you want to take off and reinstall multiple times.

Let’s say the panel is flat, and has a hole drill through for a bolt. You’ll have from the top typically the bolt, metal washer, panel, then whatever it’s attached too. The issue I see with this is when you torque down the bolt it will twist the washer and mar the clear coat or coating on top.

This is a cosmetic piece so I’m thinking a small thin plastic shim washer or something would work so maybe this

bolt, metal washer, plastic shim, panel, whatever it’s attached too

Or would you maybe just use a washer with one of those rubber gaskets already attached so it’s almost like a 2 in one piece.

Just seeing what others are doing or any tips.

#2

What about using something along the lines of this? - http://www.raceways.co.uk/Bore_size_conversion_Sleeve_nut_washers.htm

That way the bolt head will only rub against the top of the metal sleeve washer. You’d need to get the correct sleeve length, which may be tricky to find unless you grind it down a bit?

#3

Yeah I thought about that but there has to be another way. It could work but the item posted above you’d have to fab up more hardware to make work.

#4

How about a threaded rivet ?

#5

Na, threaded rivet doesn’t work. It’s a flat cover that has a 1 inch 1/4 plastic spacer below it so if that helps any.

#6

Do these guys have something for you:

www.bighead.co.uk

Or some of the neat looking aircraft solutions.

#7

Nylon hardware? How strong does this need to be? Nylon nuts, bolts, washers, spacers are readily available and insanely strong. I’d bet you can even special order colors (if this is a production item).

#8

Ah nope, but thanks for the link though, I’ve been semi looking for something like that just encase for future projects

It has to withstand engine vibration and I guess as much as a M6 allen bolt torque can withstand so 16lbs?

I just need something to protect the metal washer from the clear coat but if all else fails I’ll probably not put anything just because it doesn’t seem like anybody does or they would have a solution.

#9

How about a rubber washer? The rubber washer may stick slightly to the clear coat meaning the bolt will just turn on the washer without the washer turning on the panel. The bolt would probably stand up to engine vibration without working loose.

#10

Can you still design females into the underside and bring fasteners through the frame, into the underside, without piercing the “show” side?

#11

Yeah I actually used a rubber washer before. The issue with them or the ones off the shelve of a big box store is they’re pretty soft so when the bolt was torqued down the metal washer crushed it. Then I drove a few days with the part attached and it was slightly looser than before so I assume it was because of the contraction or flexibility of the rubber.

I know what you’re saying I think. But it wouldn’t look right with a concave bolt attached.

#12

I don’t know what a concave bolt is. What I’m thinking is the fastener would pass through your frame, into the underside of the composite panel, where it tightens down without passing through to the show side. You won’t see anything on the show side. Just your glossy finish.

#13

Oh I mean a concave hole for the bolt I meant. I don’t care if the bolt shows. I’m just seeing if anyone has dealt with bolts and washers and used something in between to protect the clear coat.

#14

How about a sacrificial bit of electrical tape or duct tape stuck to the panel? Cut it to the shape of the metal washer so it won’t be seen.