Need to remove 2 screw in steel bosses in an aluminium frame
Not corroded but in damn tight with locktite I assume. Flats have started to round off nicely not helped by the fact they are the traditional 8.5mm rather than a size you might have a spanner for.
Penetrating fluid not done a thing.....how much heat can I apply without damaging things?
New frame btw so don't want to ruin paint
Use a soldering iron to localise the heat on the bosses. It shouldn't take much (unless you used stud lock!)
Nice tip that* 🙂
*Said the actress to the bishop.
New frame btw so don't want to ruin paint
Unless you never ride it, the paint will get chipped and scratched in no time anyway 😀
Hot air gun or blowtorch, apply heat to the stud not the frame and let the heat flow down the stud into the threads/loctite. Most Loctite is designed to break down if enough heat is applied.
piping hot water
If the heat treatment doesn't work then a set of mole grips will do the job. It will probably wreck the bosses though.
Well I'm stumped. I've tried a 40w soldering iron, mole grips and I'm left with a mangled boss and a bad temper.
Any other suggestions? The idiots in the factory must have glued them in I guess?
Tell me its not a reversed thread
Why do you want to remove them ? If its a cross frame and its got disc mounts your going to use I'd just saw them of and touch up with a bit of paint.
It won't be a reversed thread as otherwise tightening up canti bosses on installation would risk looseningthe reverse threaded boss and starting the slow process of it winding itself out of the frame with the back and forth rotation of canti arms.
8.5mm is a silly width. I reckon dremel or file it down bit by bit to make good straight 7 or 8mm flats and a tight fit in a good quality proper spanner (ie not adjustable, i guess that didn't work already)
Also wondering bearing in mind the strange 8.5mm bit if its possible they are indeed not threaded at all but bonded into the frame or something daft like that.
If the bosses are mangled then maybe a Dremmel and cut them flush? Or some reverse threaded removal gadget?
Deffo threaded - you can see the threads underneath. Plenty of pics on the net with the bosses removed so can be done - just not by me!
Tried a nice adjustable first (Bahco)
Think I'll just have to hacksaw them off and file down as suggested.
Get a M6 screw long enough to screw into the boss plus two new nuts. Screw both nuts down the screw. Screw the screw with nuts into the canti boss then tighten one nut down hard onto the boss, whilst holding the screw stationary. Tighten the other nut down hard onto the first nut, whilst holding the first nut stationary. Use a good ring spanner on the first nut to unscrew the boss.
A decent set of Irvin 10" vice grips with curved jaws [i]would[/i] get them out, the more pressure you apply, the more the curved jaw will dig in to the boss rather than spin which is usually the case with straight jaw grips. Failing that a set of stilsons would get them out.
Easy out into the top of the boss ( the boss won't survive ) use with heat as well
Stick the boss in a vice and rotate the frame?
How much heat can I safely apply without destroying the paint on the stays
If the loctite is red it'll need quite a bit of heat to get it out. Some doofus PO red loctited some motorcycle disc bolts in on a race bike we had and we ended up having to weld something on to the bolt heads and keep heating the bolts while we turned them to get them out.
Done it.
Red Loctite that had been in the frame since 2005 (as frame is nos)
80w soldering iron from underneath till boss was far too hot to touch then 10" vise grips
A beer I think.....
