Morris Minor Owners Club

I am doing my interior wood at the moment and replacing the rusty screws with stainless ones so that the darkening of the wood caused by the rust leeching into the wood from the screw's wont happen again.
Does anyone know if the ones that go though the timber into the `B` post are available in stainless or is there a foolproof way of protecting the original type to stop this leeching from happening.

Hi Kevin.

The large screws that go through the wood into the B post are called 'ACME' screws and are zinc plated from new. The cause of staining, is the captive nuts they screw into in the B Post are mild steel, and the corrosion comes from there, creeps along the screww threads, and hence causes the staining. A coat of copperslip on the threads stops it, as does wrapping the screw threads with some PTFE joint sealing tape.

Another tip, is to liberaly coat the holes in the wood with Burgess Wood Sealer, this further slows down any staining.

Hello Kevin,

as far as Stainless fasteners go, being BSF these may take some finding with the original Philips head, hexagon headed bolts would be no problem .
Certainly, over a long time the plated original screws can lose their protective plating so Stainless would help as long as they are a grade (strength) equal to the original (I'm afraid that I don't know what the original grade was?)
Personally, I do not like Stainless fasteners but that is me.

Alec

I wouldn't use stainless bolts as it will cause the mild steel captive nuts to rust even more due to bi-metallic corrosion. Do as said above, use copper grease and waxoyl the inside of the B pillar.

Thanks for the input guys it looks like my bolts may actually have some varnish on them that has discoloured and if the zinc plating is still good I will stay with that.
Is the best way to remove them by using an impact driver as I assume they will be a bit of a so and so to remove and I may even put this off till later in the year as the interior bits I have started has already grown into 3 times as much as I thought and then there is the engine re-build before the rally season so time is already starting to run away from me.

Is the best way to remove them by using an impact driver

They usually come out quite easily, but the screwdriver bit needs to be a snug fit. I forget the exact size. I used a small wrench with 8mm socket, with the bit fitted into the socket. Try this before an impact driver to save splitting the wood, or dislodging the nuts in the B post.