Stainless screws corrosion?

I've just fitted a stainless steel sill to the back door frame (going to do the sides next). The screws from the old sill are crappy grey steel (possibly galvanised) and went straight into the frame, so I used some nice stainless ones... then thought about it.
I guess the door frames are aluminium alloy so corrosion may be an issue. I know there are loads of " theoretical" problems (e.g. with boats in seawater) but keeping it real:
Has anyone actually used stainless screws straight into alloy bodywork? Are there any real problems worth noting (i.e within my lifetime - about 40 years)?
Cheers for any help,
Matt

Frame is steel but yes the skin is alloy. A little blob of silicon sealant or similar in the holes will isolate screw from bodywork and should stop electrolytic corrosion. Though its not a speedy process my Landy is 40 years old and in places the corrosion is pretty bad, mostly rad panel to wings, and it only takes a moment to do so you might as well

I rebuilt my 90 with a brand-new body and SS fixings throughout 11-years ago and corrosion hasn't been an issue, just make sure you apply something like a dab of Waxoil on the threads as you put it all together (that's what I did).
The only place I have noticed some corrosion was about 3-years ago and that was at the tabs where the tub is bolted to the rear crossmember but that was between the crossmember and the body (not the SS fixings) so I isolated them with thin strips of plastic.

Litch said:

I rebuilt my 90 with a brand-new body and SS fixings throughout 11-years ago and corrosion hasn't been an issue, just make sure you apply something like a dab of Waxoil on the threads as you put it all together (that's what I did).
The only place I have noticed some corrosion was about 3-years ago and that was at the tabs where the tub is bolted to the rear crossmember but that was between the crossmember and the body (not the SS fixings) so I isolated them with thin strips of plastic.

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Cheers! Will take them out, waxoil and stick 'em back in
Matt

I put Chequer plate sills on mine with stainless screws, and after a year there seems to be signs of electolysis, so yeah, use some silcon to insulate it or something

Came across this while browsing Duralac Anti Corrosive Compound PB DL-0115 Llewellyn Ryland
But I guess silicon and wd40 as suggested would do just as good a job - cheaper too!

You could always use Inkernol fastenings ... totally inert but expensive!

OSD

Oldseadog, can you let me know where these fastening can be sourced/
Cheers

Legion said:

Oldseadog, can you let me know where these fastening can be sourced/
Cheers

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Try these people and explain what you want to do.

Sorry, I couldn't remember how to spell it ... The product is either Inconel or Inconnel, and they used to be available as nuts & screws or self-tappers.

My usual supplier is no longer in business! Mind you, last time I used them it was over 10 years ago!

Good luck.

OSD

You can get fibre washers, we had some when we bought a new galvanised shed.

Silverline 797967 Fibre Washer Pack 110pc

This sort of thing, but in the sizes you need...