Weather seal an m42 adapter?

[d.bradley]

Hi folks,

I am planning on modifying a PK-m42 adapter to be weather sealed. It may be an ambitious project, but one worth trying I feel.

First...since the adapter is accessible from both sides, it should be possible to put a seal on the body side as well as the lens side. My hope is to machine a groove around the adapter where it contacts the metal body mount, and add an appropriately and small amount of some material that will extend just slightly above the height of the adapter and create a seal.

My questions: what material would be good? I am thinking a caulking or some kind of glue might suffice. The substance needs to be able to compress to form the seal and adhere well enough to the grove to stay put. Something too mailable runs the risk of being torn under the twisting forces of adapter mounting...so finding the right substance is key.

The other option, which I haven't explored, is to fit a pre-made gasket into the groove...I don't know what is available, or what might work. It would also have to be adhered to the adapter...which I feel might be overly complicated relative to using the adhesive itself as the seal.

So...what do you think? Will this be possible? Any ideas on sealing substance or other construction methods?

Thanks!
Damian