My 105 Sprint GT had a cylindrical-shaped fuel filter made of bronze mesh around the pick-up tube that extends down from the sending unit to the bottom of the tank. Unfortunately, the mesh was broken at the base, rendering its filtering properties null.
Now this filter probably isn't essential - there are a few filters between the tank and the carbs. But, if Alfa decided that one should be there, then I'd like to replace it.
Seems that I have read of other Alfisti getting mesh material from McMaster Carr, and duplicating the in-tank filter. It would seem that you could take a circle of mesh about 6" dia., and create a "bundle" around the end of the tube, securing it with an accordian-style hose clamp. Not pretty, but it should work as well as the original cylindrical filter. But, what sort of mesh to use?
McMaster Carr sells a LOT of different styles of woven wire cloth. My question is the gauge of the weave. M-C measures it in terms of wires/inch. They have mesh as fine as 1500/inch, though I would guess that about 50/ would be as fine as the original Alfa filter material. Too fine, and it will clog up, too coarse and it won't filter out the crud.
Has anyone tried duplicating this filter? If so, what sort of woven mesh did you use, in terms of wires/inch, and wire material (bronze vs stainless vs copper)?
The new replacement fuel senders available from the usual parts suppliers actually have a plastic mesh basket over the inlet, which is secured with a zip tie of all things.
I've had a look at the weave on the bronze original basket and it is quite fine, but by comparison the weave on the new replacement is quite large.
I can't show you a pic of the new one as it's in my fuel tank (strangely enough ), but here's a pic of the original.
To be honest though, I don't think the purpose of this mesh is to actually filter small particles at all. I would think it is just there to prevent the pickup from being blocked in the event that a single large item of debris, such as a stray leaf or paint flake may find it's way into your tank and foul the inlet. (don't ask me how a leaf would get in there, but I'm sure it's possible).
If I were making a replacement I would think that a double layer of stainless fly mesh would do the job as well as the plastic mesh, but looking at the original I would guess you'd be looking at something close to 100 wires/inch and you'd be about spot on.
If you want to be really accurate, you can count 'em from the pic