Painting Diecast Boxes

[Brian Reay]

Anyone found a way to paint diecasr "Eddystone" boxes so that the paint
doesn't rub off with wear?

In the past I applied "alochrome", followed by an etching primer, then the
top coat. Seemed to wear quite well, but my stock of alochrome liquid is
getting low and I understand it isn't easy to buy in small quantities these
days.

[Jeff]

Post by Brian Reay
Anyone found a way to paint diecasr "Eddystone" boxes so that the paint
doesn't rub off with wear?
In the past I applied "alochrome", followed by an etching primer, then the
top coat. Seemed to wear quite well, but my stock of alochrome liquid is
getting low and I understand it isn't easy to buy in small quantities
these days.

I have found that car spray paint, baked in a cool oven or environmental
chamber is reasonably hard wearing.

73
Jeff

[Brian Reay]

Post by Jeff

Post by Brian Reay
Anyone found a way to paint diecasr "Eddystone" boxes so that the paint
doesn't rub off with wear?
In the past I applied "alochrome", followed by an etching primer, then
the top coat. Seemed to wear quite well, but my stock of alochrome liquid
is getting low and I understand it isn't easy to buy in small quantities
these days.

I have found that car spray paint, baked in a cool oven or environmental
chamber is reasonably hard wearing.

Which type, acrylic or cellulose based?

I once, in error, sprayed some aluminium with "Bath Power" cleaner. The
aluminion took in a tough to remove grey/black colour. I did wonder if this
would mimic alochroming for the purpose of painting.


__
73
Brian
www.g8osn.org.uk

[Jeff]

Post by Brian Reay
Which type, acrylic or cellulose based?
I once, in error, sprayed some aluminium with "Bath Power" cleaner. The
aluminion took in a tough to remove grey/black colour. I did wonder if
this would mimic alochroming for the purpose of painting.

cellulose

73
Jeff

[From the shack of G1LVN]

Post by Brian Reay

Post by Brian Reay
Which type, acrylic or cellulose based?
I once, in error, sprayed some aluminium with "Bath Power" cleaner. The
aluminion took in a tough to remove grey/black colour. I did wonder if
this would mimic alochroming for the purpose of painting.

cellulose

What's that blue stuff you rub in? Carbon Black?

I remember we used to bring our air rifles into metal work lessons at school
to apply the said treatment to the metalwork

(you probably wouldn't get away with it these days).

[Theo]

Post by From the shack of G1LVN

Post by Brian Reay

Post by Brian Reay
Which type, acrylic or cellulose based?
I once, in error, sprayed some aluminium with "Bath Power" cleaner. The
aluminion took in a tough to remove grey/black colour. I did wonder if
this would mimic alochroming for the purpose of painting.

cellulose

What's that blue stuff you rub in? Carbon Black?
I remember we used to bring our air rifles into metal work lessons at school
to apply the said treatment to the metalwork
(you probably wouldn't get away with it these days).

You would probably be shot by Mr Blur's power force as a
terror suspect!

Ich bien auslander - nicht verstanden!

[Theo]

I find one of the best ways to etch sheet aluminium and diecast boxes to
provide a good "key" for painting, is to immerse the item in a strong
solution of caustic soda (Sodium Hydroxide) in cold water.

Usually 50g of soda to 3 litres of water is a good starting point - but
ALWAYS slowly add soda to COLD water, whilst stirring with a wooden stick,
NEVER add water to soda, as heat is generated during the mixing process!

It is advisable to do the etching outdoors using an old plastic bucket, DO
NOT SMOKE and keep well away from the bucket whilst the etching takes place
as explosive hydrogen gas is liberated as well as caustic spray from the
bubbling.

Once the reaction gets going, leave for about 3-5 minutes (depending on the
strength of solution), then remove the item, wash thoroughly in several
changes of clean cold water, finally under a running tap until all traces of
the caustic solution have been removed.

Taking care not to get finger marks on the newly etched surface, allow the
item to fully dry before spraying with paint, at least two good coats is
usually sufficient.

[Toxic Waste]

Post by Brian Reay
Anyone found a way to paint diecasr "Eddystone" boxes so that the paint
doesn't rub off with wear?

If they needed fettling, I could tell you where NOT to send them ;-)

Regards
tox

[Brian Reay]

Post by Toxic Waste

Post by Brian Reay
Anyone found a way to paint diecasr "Eddystone" boxes so that the paint
doesn't rub off with wear?

If they needed fettling, I could tell you where NOT to send them ;-)

How was the rally today? I got tied up with some jobs here and the morning
just slipped by to the point it was too late to come.

Not sure when the next one is but I hope it isn't long- I need some bits and
bobs.

__
73
Brian
www.g8osn.org.uk

[Toxic Waste]

Post by Brian Reay
How was the rally today? I got tied up with some jobs here and the morning
just slipped by to the point it was too late to come.

Lots of people there...

Post by Brian Reay
Not sure when the next one is but I hope it isn't long- I need some bits
and bobs.

* 12 February *
Harwell ARS Radio & Computing Rally, Didcot Leisure Centre, Mereland Road,
Didcot, Oxon.

Hope to see you there...

tox

[Technological Hierarchy for the Removal of Undesireables and the Subjugation of Humanity]

Post by Toxic Waste

Post by Brian Reay
Anyone found a way to paint diecasr "Eddystone" boxes so that the paint
doesn't rub off with wear?

If they needed fettling, I could tell you where NOT to send them ;-)
Regards
tox

A door needed fettling on Corry st tonight.......

[Theo]

Tox, did you spot the T.S. at Horncastle?
New one on the rally circuit ?

[Dave]

Post by Brian Reay
Anyone found a way to paint diecasr "Eddystone" boxes so that the paint
doesn't rub off with wear?
In the past I applied "alochrome", followed by an etching primer, then the
top coat. Seemed to wear quite well, but my stock of alochrome liquid is
getting low and I understand it isn't easy to buy in small quantities these
days.

The modern method is to anodise the metal. Alocrom, note the spelling,
went out of favour in the aerospace industry some time ago.

The etch primer went the same way at the same time.

These days, you anodise, epoxy primer and final paint coat.

Epoxy primer lasts less that 24 hours.
Alocrom lasts for about (if my memory is right) 48 to 72 hours.
Etch primer, I can not remember how long it lasts for.

HTH

But ask PK, in any of his modern forms, to confirm this.

Dave

[Jeff]

Post by Dave
The modern method is to anodise the metal. Alocrom, note the spelling,
went out of favour in the aerospace industry some time ago.
The etch primer went the same way at the same time.
These days, you anodise, epoxy primer and final paint coat.

The problem with anodising is that the finish is a very poor conductor.
Alocrom is still used extensively in avionics equipment. However, some
formulations of Alocrom are also quite poor, particularly at RF. You have to
make sure that you use the right one. (or in expensive military equipment
use gold flash).

73
Jeff

[l***@eternal-flames.gov]

Post by Brian Reay
Anyone found a way to paint diecasr "Eddystone" boxes so that the paint
doesn't rub off with wear?

1. Remove any old paint.
2. De-grease the box with Hammerite Brush Cleaner.
3. Apply a coat of Hammerite Special Metal Primer.
4. Apply a coat(s) of Hammerite.
5. Sorted.

[Paul Shayler]

Post by Brian Reay
Anyone found a way to paint diecasr "Eddystone" boxes so that the paint
doesn't rub off with wear?

1. Remove any old paint.
2. De-grease the box with Hammerite Brush Cleaner.
3. Apply a coat of Hammerite Special Metal Primer.
4. Apply a coat(s) of Hammerite.
5. Sorted.

This sounds a good and reasonably cheap way to do the job. All the
"Hammerite" materials should be available from B & Q. Having worked in
the paint/coatings industry in various technical areas, I know it can be
sometime a problem to paint some metals to give a durable finish. I'm
currently involved in Automotive OEM coatings. Please do take time to
follow the manufactures safety guidelines printed on the containers when
using any paint/paint related products.

Regards, Paul S.