PDA

View Full Version : One for the metalurgists et al please?



gavinwibrow
10th June 2013, 03:19 PM
I have a renovation issue which is going to mean installing mild steel? frames (galvanised and powder coated cos I live near the ocean) into existing openings to support cedar/oregon external but protected french doors and triple parliament ideally brass hinges.
I'm concerned about electrolysis between frame and hinges. Can I resolve this by using stainless steel screws, or am I stumped, or????

p38arover
10th June 2013, 04:15 PM
20 years ago I asked a similar question when a steel-framed building on Norfolk Island for which I was managing the repairs needed owing to severe rusting (it was at the top of the cliff at Anson Bay).

I was advised by the civil and structural engineers to not use SS bolts as it was better to have the MS bolts rust away than have the building girders rust away.

Maybe that's why Land Rover don't use SS bolts to hold Defender doors onto the body.

Dougal
10th June 2013, 04:40 PM
Pretty much as Ron said. With stainless any other metal will be sacrificial. Our you can try to electrically insulate the hinges and screws. Corrosion is driven electrically. No conduction, no problem most of the time.

isuzurover
10th June 2013, 04:40 PM
Are you talking about the screws for the brass hinges???

Slunnie
10th June 2013, 05:00 PM
I have a renovation issue which is going to mean installing mild steel? frames (galvanised and powder coated cos I live near the ocean) into existing openings to support cedar/oregon external but protected french doors and triple parliament ideally brass hinges.
I'm concerned about electrolysis between frame and hinges. Can I resolve this by using stainless steel screws, or am I stumped, or????

The steel is sacrificial compared to SS and brass. I would recommend using the same metal for all parts - ie Galvanised steel.

JDNSW
10th June 2013, 07:00 PM
If you need to use brass hinges (decor etc) you need to insulate the hinges from the mild steel/galvanising. Nylon pads and sleeves to do this should be available from a marine chandler, as these are used on alloy masts to insulate stainless fittings. The actual fasteners would be best made of galvanised mild steel, but you could use brass and insulate this from the steel, or stainless steel is not a major problem against mild steel, but should be insulated from the brass.

John

gavinwibrow
10th June 2013, 10:10 PM
Are you talking about the screws for the brass hinges???
Yes Ben, the screws through the brass hinges into the mild steel framework ie the screws make the metal to metal connection.
It sounds like from most posts above I should at the very least stay with galv screws - then maybe paint the heads brass to match the existing hinges, handles and security bolts?
EDIT - just read John's post - I think he is on the money

isuzurover
10th June 2013, 11:52 PM
Yes Ben, the screws through the brass hinges into the mild steel framework ie the screws make the metal to metal connection.
It sounds like from most posts above I should at the very least stay with galv screws - then maybe paint the heads brass to match the existing hinges, handles and security bolts?
EDIT - just read John's post - I think he is on the money

Yes. Duralac is probably sufficient for your purpose.

Richard93Vogue
12th June 2013, 05:47 PM
20 years ago I asked a similar question when a steel-framed building on Norfolk Island for which I was managing the repairs needed owing to severe rusting (it was at the top of the cliff at Anson Bay).

RonB, was that on the cable hut for the telecom cable?

The wife and I lived on Norfolk for a while a few years back. Beautiful place.

uninformed
14th June 2013, 02:25 PM
I have a renovation issue which is going to mean installing mild steel? frames (galvanised and powder coated cos I live near the ocean) into existing openings to support cedar/oregon external but protected french doors and triple parliament ideally brass hinges.
I'm concerned about electrolysis between frame and hinges. Can I resolve this by using stainless steel screws, or am I stumped, or????

Is there an option to go S/S frame and hinges? what you spend extra on the S/S you save on the Gal and P/C. Btw, gal works better if it is exposed. Have you considered brass screws?

gavinwibrow
14th June 2013, 04:29 PM
I'm actually reversing 2 sets of french doors to open inwards, so we can then have secuity french doors on the outside.
This means I have to stick with brass hinges and screws to maintain the internal visual impact for the rest of the room/s.
The uprights for the new inside wall leaf door frames need to be solid metal 50 mm wide and 25 mm deep as I dont think timber plugged into the brick walls would be strong enough, given the weight of the admittedly light timber oregon door frames, but with lots of heavy glass.
I suspect s/s in this sort of size would be very expensive, but will check.

I will then tap through the metal and fit countersunk threaded bolts.

roverrescue
14th June 2013, 05:10 PM
50 x 25 in stainless would certainly be cheaper than the same in FMS, gal dipping then powdercoating.

Its not exactly a large section size. And 316 bar stock is cheaper comparitively than 316 tube stock against mild steel.

But having said that, there will be a way to use timber framing for the doors and still maintain its security status.

S