AVO 8: Scaleplate Cleaning. What's Best?

[russell_w_b]

What's the best method of cleaning an AVO scaleplate? There're a few mildewey spots on it and it's a little bit grubby. I'm loathe to detach it from the movement and attempt to clean it until I know best what to use without risk of damage.

Anyone?

[pmmunro]

Russell,

The safest treatment is possibly going to depend on the age of your meter. Up to c. 1964, the scaleplates had the radial lines ruled in by hand using Indian ink which will be soluble in water. Once the move was made to selected scale plates, I don't know how the markings were printed or how durable they are.

Your need is similar to fine art picture restoration and that might give you some leads. I know that one of the techniques involves stale bread, probably as a very gentle eraser.

In any event I think it would be best to remove the scaleplate from the movement frame. I know I don't need to tell you this needs to be done carefully and the pointer needs especial protection but someone less experienced may read this post later.

PMM.

[russell_w_b]

Originally Posted by pmmunro

The safest treatment is possibly going to depend on the age of your meter. Up to c. 1964, the scaleplates had the radial lines ruled in by hand using Indian ink which will be soluble in water. Once the move was made to selected scale plates, I don't know how the markings were printed or how durable they are.

Your need is similar to fine art picture restoration...

Thanks, PMM; appreciated. The meter was made in May 1963. Fortunately, the muck is below the lettering on the lower part of the scale, apart from the odd patch of brown at about 75% upper scale.

[russell_w_b]

I'd removed the mirror and was cleaning it with a spectacle wipe and I thought: 'hmmm...' I tried the spec wipe on the back of the scaleplate and it worked a treat!

So I used it a fresh one the front of the scaleplate to good effect. Apart from a 'stubborn stain' (I've seen worse) I got shot of all the mildewey grime.

[Palmerino]

PMM

My personal experience on approximately twenty scale plates.

After they have been dismanted and dust with a soft brush , then, I washed with water and little soap (marsiglia solid) using a soft cloth with care. Probably I was lucky because the result was very good. Only recently with a Avominor type 2 inscriptions have faded but I probably pushed too much. I agree with you to use extreme caution. I as precaution before cleaning them I make photocopies. Do not use alcohol or other solvents absolutely on pain of immediate liquefaction of the fund. On a very old scaleplate cracked I used one office whitening as underpainting on which I laid out in little touches the pen color retouching car body. I couldn't retouch with satisfaction lettering and lines, the smallest nib I found is 0,1mm and is too big.

Ciao, Palmerino.

[Phil G4SPZ]

I find that 'baby wipes' are good for cleaning practically all parts of an Avometer without causing damage. Some brands do leave a residue, however, so a spectacle wipe sounds an interesting alternative.

[russell_w_b]

Originally Posted by Phil G4SPZ

Some brands do leave a residue, however, so a spectacle wipe sounds an interesting alternative.

It was a non-alcohol content spec wipe, I might add. There are different types!