darukhan

Dear fabrication gurus....

I need to fill a hole in 7005 series butted aluminum. Once the hole is filled, I'd like to thread tap the spot that was filled. I've already tried using JB-Weld and it just doesn't hold up to the thread tapping process like I need it to.

Is there a DIY alternative to welding this this hole?

Here's what I'm trying to fix.... the top pic is what it should look like (not my actual bike) while the bottom pic is my actual bike frame that I'm trying to repair (without having to find someone to weld it).

Should I just get it welded? How much would that cost roughly? Any advice would be appreciated!



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(NOTE: This is NOT a critical part to the bike.... it's simply a bolt that a plastic latch connects to on a folding bike. It does not interfere with the performance of the bike while riding or folded in any way. The only negative thing about not having this latched, is if you lift up the bike off the ground, the rear swingarm drops. In other words, it would only be a problem if I were jumping or doing tricks on this bike which I'm definitely NOT doing... it's my commuter bike that I take on a train everyday!)
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Pic of the whole bike in case you're curious...

BenCooper

Ah, an older Birdy. If it was me, I'd tap the hole to 6mm (it's 5mm at the moment isn't it?) and use a larger bolt, perhaps with the bolt head filed down a bit. That should still work fine with the "frog", the plastic catch thing.

Other option is to drill it larger and fit a rivnut. Welding would be a huge amount of hassle.

unterhausen

I agree with Ben on the possible solutions. Do you have access to the back so that you could use a nut?
Welding isn't really a feasible option in this case

Dancingbear

Another thread repair option that works well is a helicoil. Downside is you need the tools in the proper sized kit to install, and the kits are pricey. If you can find someone who has the right size kit then it would be my first choice.