removing stainless screws from aluminium window frame

[ghostlymoron]

One of my windows is leaking so I have to split the frame to re glaze it. The two halves of the frame are held together by fishplates I assume which are secured with stainless screws. I've doused them in plus gas but they still won't budge. I'm thinking maybe some got water may dissolve the oxide holding them in or perhaps soak in a dilute acid. (Oxalic?) I'm reluctant to use a blowlamp or air gun as I don't want to crack the glass. Is there anything else I can try before resort in to drilling the heads off?

 

[Concerto]

Sometimes using a hammer on a screwdriver can "crack" the oxide or salt corrosion. Alternatively lots of very hot water can also work.

 

[ghostlymoron]

Update! Plusgas overnight, boiling water (kettle full), hammering the screwdriver has removed six of the eight to my surprise. I'm still working on the other two but the ends have got slightly damaged now so the screwdriver slips. One more try and then its out with the drill unfortunately.
Thanks for your speedy reply.

 

[Adamastor]

Impact wrench! Beats the hammer/screwdriver any day of the week, and they're actually quite cheap- <£10 I'd say...

 

[Norman_E]

I have owned two impact wrenches, both of which have been pretty useless. Maybe its just bad luck but neither appear to be any better than trying to shift a reluctant screw with an ordinary screwdriver.

 

[Seajet]

Dremel with cutting disc then ( with loads of plus-gas ) pin-punch the fastenings round ?

 

[Pye_End]

I found the most useful tool for this job was a brace. Almost all of the screws eventually gave up and came out, though one fixing has snapped below the head(grr). Also used a hot air gun, though no idea if it helped or not.

 

[alan]

Removing Steel Screws in Ally

Have a look on U-Tube for video showing how to remove screws used for mounting car brake disk to hub. Not the same situation, but shows using a "spike" to gently tap the screws out. Apparently this system is better than heat or impact drivers etc. Just needs a bit of patience. Ask any MGF/TF owner about removing brake disks and they will probably tell you to use a "spike" or small round "drift".


Link: https://www.youtube.com/watch?v=q1c6uEDj5Rw


Alan.

 

[BruceDanforth]

I removed all deck fittings and windows last year and got all of the bolts out by giving the nuts a quick blast with the torch attachment of one of these:

http://www.maplin.co.uk/p/pro-iroda-solderpro-50-gas-soldering-iron-n11ar

It gives a tiny blowlamp small enough to target on a single nut or machine screw. Nothing cracked or caught fire - just some minor singeing of paint. I kept a bucket of water to hand just in case though.

I used this stuff to help get the frames out of the boat and to remove the glass.

http://www.marinechandlery.com/debond-marine-formula


I rebuilt the windows with a bostik sealant from Wickes then rebedded everything on polysulphide (also from Wickes). It is messy stuff so I used masking tape and white spirit to clean up.

The seal on pretty much every cleat, winch etc. turned out to be shot but so far so good and no leaks.

 

[ghostlymoron]

I've now taken the frame apart and only had to wreck 2 of the screws. It cleaned up easily because the glass was sealed in with a rubber moulding and the frame sealed to the hull with something like butyl tape which seals well and doesn't adhere strongly. I'm going to reglaze using similar materials and the method detailed on the Seals Direct website.