Cleaning out bolt threads

[QBhoy]

Half round file and clean up the threads on the bolts.

 

[QBhoy]

Half round file and clean up the threads on the bolts.

Half moon file, rather !

 

[rotrax]

So ... what sort of anchor do you prefer?

I was in the pits at the 1967 IOM TT. A bloke I knew had got a ride on the new and outrageously wheelie prone three cylinder two stroke Kawasaki H1 in the production machine race. He was a goer and did well enough to be invited to ride in the Senior TT proper. He had it on the back wheel far more than he was comfortable with during his race. He could modify the bike for the Senior event, unlike the Proddy race where it had to be standard. He was asking for better forks and front brake.

'Black' Jack Steer, a sidecar competitor asked him " What sorta forks do'ya need mate? "

Like anchors, the answer was a classic.

" 'Eavy ones Jack, bloody 'eavy ones! "

 

[penberth3]

Half round file and clean up the threads on the bolts.

OP was asking about an internal thread.

 

[QBhoy]

OP was asking about an internal thread.

I didn’t get which it was from the OP. Although I did see many others afterwards assume that.

 

[QBhoy]

OP was asking about an internal thread.

Also more likely that the new bolts have plated issues.

 

[PaulRainbow]

I didn’t get which it was from the OP. Although I did see many others afterwards assume that.

Don't think much assuming was done, the OP said, in post#1 ;

The screws still work fine in the original corroded elbow.

It looks as though the makers were a bit enthusiastic with the primer, and there's paint in the threads. [/quoue]

 

[rogerthebodger]

Hello

I bought an after-market exhaust elbow for Penta D2 55. Seems a decent bit of kit, however I am struggling to fit the (original) water inlet using the two (original) machine screws. The screws still work fine in the original corroded elbow.

It looks as though the makers were a bit enthusiastic with the primer, and there's paint in the threads. They swear it's the same M8 thread...and it appears to be as far as I can tell.

Recommendations please to clean the threads of excess paint? Chemical or mechanical methods? I already have a heat gun, HCl and caustic soda to hand if those are any good.

Many thanks indeed.

Try putting a hot soldering iron into the threaded holes to burn the paint from the holes.

 

[RJJ]

Don't think much assuming was done, the OP said, in post#1 ;

You assumed, or didn't assume, correctly. Internal threads.

 

[Aja]

Bit like the comment from our wives when we three brothers start talking... Is that code????? for something

You talk to your brothers!?!

 

[DownWest]

You talk to your brothers!?!

Yes, we live in three different countries, so like a natter when we get together, it does tend to get technical though and knowing each other pretty well, we often use 'shorthand' hence the incomprehensibility to our wives..

 

[RJJ]

You should really run a M8 tap down the threads but in the absence of a tap you can make one from an old M8 bolt. Just cut vertical slots, 4 with a hacksaw starting deep at the end and tapering off to nil about an inch from the end. Just work it back and forward gently and the paint in the threads will go into the slots cut. Take it out clean off the thread paint and continue until the bolt goes right down.

...and job done, thanks. Dead easy now I know how. I used a Dremel with cutting disc, 5 minute job.

 

[[159032]]

I had exactly this problem with a stainless aftermarket elbow for a Volvo a few months back.

Caused me no end of grief trying to fit - exactly as you described. It turned out that in manufacture, the mating face had warped, and the bolt holes had turned inwards accordingly. As a result I could only get it part way over the bolts.

When I contacted them it turned out there were similar elbows in the stainless batch.

I returned it and fitted a genuine Volvo instead. I would have preferred stainless but I'd already paid to have the face milled flat before I realised it wouldn't go over the bolts, so had had enough by then.

Often will happen on a welded manifold. The exhaust specialists weld the pipe to the manifold plate on the inside of the pipe. The pipe is slightly set back in the manifold plate. It looks fancier to have a nice weld around the outside of the pipe, but may distort the plate.