Black 746 phone - what's the best polish for scratches?

[whereistom]

Hi,

I have a black 1973 746 that I'm doing up, and the plastic is quite scratched - general usage scratches mainly, but one nice zig zag down the side which was presumably done by someone who was bored with a compass! It's also a bit faded in places.

So first question - what would people suggest to remove the scratches and restore the colour? Ideally I want something easily available (so not waiting two weeks for something to arrive from the US!)

And second question - what kind of plastic are the 746s actually made from?

Thanks very much!
Tom

[nickn05]

I've been recommended one or two different things for getting the 746 cases sorted out, what I currently use is:

1) 0000 Steel Wool for first attempt, good for quickly losing scratches.
2) Silvo Wadding (Duraglit) for second attempt.
3) Plastic Polish No. 5 from Greygate for final polishing (easily obtainable on Ebay)

However some people have said that standard T-Cut is very good for initial rubbing, followed by a furniture polish or even WD-40 for the final gloss.

No doubt there are other good ways of doing it too.

As for material, the 746 cases are made of ABS (Acrylonitrile Butadiene Styrene), a thermoplastic.

If you have fading on the case, polishing may not help, as some fading is a natural eventual product of sunlight on the phone - I have had good success so far with a modification of the Retrobright process (basically 10% solution Hydrogen Peroxide wet bath plus tiny amount of Oxy Stain Remover powder, sat in sunlight or under a ReptiGlo UVB lamp for several hours) on ivory cases, but not tried dark colours yet.

[russell_w_b]

Originally Posted by nickn05

If you have fading on the case, polishing may not help, as some fading is a natural eventual product of sunlight on the phone - I have had good success so far with a modification of the Retrobright process (basically 10% solution Hydrogen Peroxide wet bath plus tiny amount of Oxy Stain Remover powder, sat in sunlight or under a ReptiGlo UVB lamp for several hours) on ivory cases, but not tried dark colours yet.

I tried it on a green 706 without the Hydrogen Peroxide: warm water with a dollop of Aldi oxy-stain remover stirred into a solution: three days in diffused sunlight. It sort of worked, but didn't remove all the brown - much better than it was, though!

I've since obtained a UV lamp for another attempt on a cream 746.

[cheerfulcharlie]

There is a product called Silicone Shine which prof car sellers use to tart up plastics in cars such as dashboards etc and therefore you will probably find it in Halfords.

Its only temporary (you might have to dust it again in a month or so) but its good at filling and hiding scratches and cracks etc and putting a nice shiny gloss on things.

no idea if it works on old telephones.

[stitch1]

I used liquid Brasso and then polished with beeswax spray polish, I haven't tried it but I'd also use T-cut for deeper scratches.

Stitch

[SeanStevens]

T-Cut works well on two levels as it dissolves dirt and abrades.

It can help with the colour as it removes a layer of plastic - one hopes the plastic below is more like the original colour!


SEAN

[whereistom]

Thanks for the advice everyone, really appreciated.

Is the oxy stain remover this sort of thing (a powder)? Oxy stain remover on Sainsbury's website

And there's a few different types of T-Cut available - is this scratch remover what I might want? T-Cut scratch remover on Halfords website

Originally Posted by russell_w_b

warm water with a dollop of Aldi oxy-stain remover stirred into a solution: three days in diffused sunlight.

Dumb question - does it stay in the solution for that time, or do I soak it and take it out, and then leave it in sunlight?

And is a windowsill in cloudy UK February sunlight going to be any good at all?

Sorry for the newbie questions

[russell_w_b]

Originally Posted by whereistom

Dumb question - does it stay in the solution for that time, or do I soak it and take it out, and then leave it in sunlight?

And is a windowsill in cloudy UK February sunlight going to be any good at all?

Sorry for the newbie questions

I left it in all the time - just sitting out on the lawn, although I adjusted the container to follow the sun. I can't answer your other question: you'll have to have a go yourself and report back!

There's a bit about this sort of thing on Sam Hallas' web-site.

[nickn05]

Only thing I would say is that I found using a wet bath of purely 1-2 tsp Oxy Stain Remover (Astonish, in my case) dissolved in warm water caused a white coloured 'bloom' to appear in patches on the ivory case - looking at the Retrobright Wiki pages this seems to be the effect of wrong proportions: using too much Oxy (TAED) and not enough Hydrogen Peroxide being generated.
The bloom did polish off eventually but was a bit disconcerting!

Whereas the 10% Hydrogen Peroxide wet bath with tiny amount of Oxy works much better - though costs a little more, it can be used several times.

Even on a cloudy day outside, it works much faster that way than using a UVB lamp, which takes 48 hours + .

[whereistom]

An update, having just spent a couple of hours working on the phone:

A combination of the cold day (Sam Hallas suggests temperature of the solution is important) and the offer of some free T-Cut from a colleague meant I decided to try the T-Cut first.

There's a noticeable difference in the faded areas. There's definitely a more uniform nature to the black now, with only a few small faded areas left which could probably be solved with another hour or so.

It has also worked well on general scuffing all over the phone. Less successful, however, with the deep scratch - if anything it's more noticeable now that the rest of the phone is getting shinier! It's definitely smoothed it out, so perhaps a few more buffs with the T-Cut would work, but I'm not holding out too much hope

Thanks again for all the advice and suggestions - and if I find any better way to deal with the scratches I'll post them here.

[nickn05]

I've started using T-Cut too and find it excellent for bringing the shine out, but I always start by using the 0000 grade steel wool (Liberon) for getting rid of all scratches, then Silvo to bring back the smoothness after the rougher steel wool finish, then T-Cut to give the shine, followed by a quick splash of Pledge Furniture Polish. All takes a while but well worth it.

[sweetnovember68]

It is difficult if not impossible to simply polish out a scratch - especially as it is below the surface level of the other material around it...

For plastic polishing the steps can be - should be - are the ones that I use.....

1. Remove surface scratches using a good grade wet & dry used wet with some washing up liquid (keeps the paper soft). Start with about a 400 - 600 grade - move to an 800 and then you can try with a 1500 or 2000. All you are essentially doing is removing a very tiny amount of surrounding material to depth of the scratch. The choice of grade of wet & dry depends on the depths of the scatches you wish to remove. As a test, I will start with an 800 and then check to see if I can still see scratches. If I can, then a coarser grade is required....

2. Buffing. With a 6" or 8" wheel - on a good quality grinder (ie one that will not slow down after a few minutes) - fitted with either a spiral sewn buffing wheel, or best is a string buff - use a fine grade of cutting paste and buff away. I use Plastic glo - as it is not very greasy and does not fill up detail with a white powder as so many tend to do. available from Caswellplating (I think they have offices in Europe as well).

3. Final buffing - after buffing the entrire part - it will look a million times better than before - you can buff again for a really high lustre finish with Plastic Buffing Compound and a string wheel. This will give a deep and wonderfull all over finish.

The trick is actually in step 1 to remove as many scratches using wet & dry by slowly progressing to a finer and finer grade until you have a smooth matt surface.

Do NOT be tempted to buff for too long in one place at a time - plastics absorb heat quickly and it can lead to a melting of the area. be patient and move the part around and you will have a really nice finish.

Any questions let me know.

Kindest Anna

[Ronald1954]

I buffing my bakelite phones whith Brasso or Car polisch Commandant, then shoe polisch, then buffing and at the end i use Paraffine Oil great result.

Ron
www.ericofon.nl

[McMurdo]

Buffing. With a 6" or 8" wheel - on a good quality grinder (ie one that will not slow down after a few minutes) - fitted with either a spiral sewn buffing wheel, or best is a string buff - use a fine grade of cutting paste and buff away.

Did anyone else see the film of the GPO refurbishing their 700 cases like this? We saw it at school.

[hg7ffjj]

Hi,
Which sort of T-Cut are we talking about here? I've got of the blue 746's with a couple of scratches and am planning to try the T-Cut method, but wasn't quite sure whether you're talking about the stuff in the tube (this) or the stuff in the bottle (this)?
Cheers,
Jon