Respraying bakelite cabinets.

[paulsherwin]

I have an Ekco U245 with a damaged bakelite case, and Paul Stenning kindly sent me a case from a scrap set a month or so ago. This one was factory painted then repainted (very badly). My intention was to strip all the paint off and refinish the case as plain bakelite, like the original (there are other minor trim differences between the painted and unpainted U245s).

Well, it took hours and hours to clean the layers of paint off - Nitromors, soapy water, T-cut, the lot. Finally I have a naked case, but the bakelite colour is completely wrong. It's light brown with various lighter swirls in it. Brown shoe polish makes no obvious difference. The appearance is completely different to ex-factory unpainted U245s.

I'm now unsure whether to try and darken the bakelite somehow, spray it with Brazil Brown (which I've got), or turn it into a painted case by spraying it with cream paint (I don't have this). What do people think? It should be remembered that this is a cheap'n'cheerful 50s radio which won't restore to pristine condition whatever I do with it.

Thanks in advance, Paul

[Sideband]

Originally Posted by paulsherwin

spray it with Brazil Brown (which I've got),

I'd go for Brazil Brown. If you spray it, it's best to roughen the surface very slightly otherwise it may start peeling off at some point.



Rich.

[Paul Stenning]

I agree with Richard. I think they look better in brown than white, and Brazil Brown is a very good match to the original Bakelite colour.

Sorry it wasn't as good as we had hoped - but there was really no way of knowing what was under that horrible paint. I'm not surprised it took quite a lot of effort to clean it all off.

[Radio_Dave]

Paul, I suspect that Ekco left out the high gloss, coloured "gel" coat from the cabinets they knew they were going to paint?

Brazilian Brown is an excellent match for brown bakelite and if you've got some spare i'd use it.

However...Ford Radiant Red is a good match for the red version of this radio

David

[paulsherwin]

Originally Posted by Paul Stenning

[Left out high gloss] Perhaps to give a surface that the paint would key to better?

If so, it certainly worked. The domestic gloss paint was relatively easy to remove but the factory coat needed yet more nitromors, and even then it didn't all come off. It was by far the most difficult bakelite stripping job I've ever done, but then I've never stripped bakelite without the glossy finish

Best regards, Paul

[Sean Williams]

Hi Paul,

It may be worth using an etch primer for the case if you are going to paint it - Halfords sell it as bumper primer - a bit pricey, but it really bites into plastics and bakelite and gives a good barrier coat for your paint to adhere to.

Cheers
Sean

[Radio_Dave]

Originally Posted by Paul Stenning

I understand that it's advisable to use primer under car spray paint on Bakelite - can anyone confirm this?

I recently painted an Ekco A23 with Brazilian Brown and I used a grey primer. Everything bonded well to the bakelite and I was very happy with the result

David

[hotbulb]

I've had great success in painting Bakelite cabinets using the following method. After removing all the old paint, I rub the cabinets down with 1000 grade wet and dry paper, used wet with a spot of detergent in the water, which helps prevent the paper clogging.
After the case has been rinsed and THROUGHLY dried, use a tackrag on it to remove any dust, and then spray with Halfords Bumper Primer, which keys on very well. I normally apply a couple of coats of primer, then rub down with the 1000 grade paper again, followed by the tackrag.
The case is then ready for a topcoat of your choice. A number of thin coats are far better than one thick runny one! The finish that you end up with depends entirely on the preparation that you put in. Oh, and it will be several weeks before the paint has properly hardened. Before then is fatally easy to mark it, as I know to my cost!

Regards

Philip

[Aerodyne]

Stripping the original paint on some of these sprayed Bakelite cabinets is extremely hard work. I've recently cleaned off another Little Maestro - awful tatty pastel blue, now very attractive 'walnut' Bakelite - but a very long, hard task. Nitromors hardly touched the paint, goodness knows what the stuff was, but it can't have been cellulose as we know it!
Anyone tried caustic soda as a stripper?
I think paint is a perfectly acceptable finish. I'd flat with 400 grade wet/dry, used wet, to give good adhesion. Cream is better than white, IMHO. Several coats of whatever final colour you choose, over a suitable red oxide, grey or white primer. Final coat can be flatted with 1200 or 1000 grade wet/dry, or polished up with T-Cut, depending on your preference for gloss or semi-gloss.
BTW I've come across a few Cossor Bakelites with grotesque swirly orangy colours, presumanly intended
-Tony

[Aerodyne]

Noticed this point:

I suspect that Ekco left out the high gloss, coloured "gel" coat from the cabinets they knew they were going to paint?

To the best of my knowledge, Bakelite moulding does not involve a gel coat in the way that, say, fibreglass lay-up does. Many years back, I was involved in the manufacture of Bakelite moulds for letterpress printing - used to produce thermoplastic or rubber 'stereotype' positive plates. The Bakelite came as a softish sheet which was then subjected to heat and pressure whilst placed in contact with a metal form containing typeset material.
Industrially, the method used is to place the requisite number of 'preforms' (small blocks of lightly compressed Bakelite powder) into the mould, when pressure and heat is used to set the thermoset. The gloss finish is entirely dependant upon the surface quality of the mould. As for Ekco, in times gone by:
To quote from the Essex Weekly News, 1935:

...raw Bakelite powder is poured into moulds and electrically treated* dies bring terrific force and pressure on the powder, resolving it into a plastic substance... the workmen use an egg timer to judge the time... and a highly polished cabinet results.

(My thanks to Jools the Bakelite Man for the original info)
I believe that no distinction was made, generally speaking, for which mouldings were left self coloured and which were painted. It is certainly true of Pilot and Ultra mouldings.
-Tony

[paulsherwin]

Well, I've sprayed it brown. The finish is quite good given my limited skills, but not an even gloss. This doesn't surprise me - I've found it's virtually impossible to get a good even gloss finish with domestic aerosols of acrylic car paint - things started to go wrong about 10 years ago, when I suppose some incredibly dangerous solvents were removed . Plastikote is better, though the correct colours often aren't available.

I'll let it dry for a few days before deciding what to do next.

The electronics have restored very well BTW - I'm certainly glad I didn't scrap it.

Best regards, Paul

[Radio_Dave]

Acrylic aerosols are hopeless!, I have given up trying to get an "instant" decent finish from them, I normally end up with a dull, patchy, orange peel effect.

I have found the best approach is to just get lots of layers on, leave it a few days to dry and then rub down gently with P1200 wet and dry in soapy water until flat and then finish off with T-Cut, It certainly worked well on my U245

Regards
David

[Aerodyne]

I couldn't agree more about the poor results obtained with Acrylic aerosol sprays compared to the old cellulose ones: but try Halford's own brand. You should be able to find a car body colour that suits your needs, whatever the project and I find they are the best around, with a clean spatter-free and high pressure fan of spray almost to the end of the can. Priming is always essential and it MUST be left to harden off for a day or possibly more before top coats are applied. Dampish weather ruins gloss finish with any aerosol, of course. Warmth and dryness essential. I do much as has been mentioned - several light coats of gloss, wet/dry (or rottenstone powder on a rag damped with turps) then T-Cut for a good gloss finish.
BTW the darker the colour the more the imperfections show: hence I use cream finish when appropriate, rather than brown!
-Tony

[Sam]

I've not used them to paint radios, but the Holts Duplicolor car paints give a good finish on metal and plactic. I have used them on a couple of Motorbikes, once for the tank, once to re-paint a GRP fairing.

I agree, the Plasitkote stuff is really good. It is my standard paint for the cycle-parts of a bike.

You can only get as good a finish as your preparation was with the sprays. I tend to use plenty of layers of primer, plenty of layers of top-coat, and a few coats of laquer. A lot of work, but it is uslally worth it!

Sam

[Sean Williams]

When painiting using any spray method you have to make sure that the paint fully "wets" the surface - too thin a coat will give a patchy "orange peel effect" - you need to apply the paint evenly to a point where the surface begins to shine - the surface has then "wetted". If you need to apply more coats do so within either 15-20 mins, or a couple of days - if you do not follow that rule, the solvents will either be trapped between layers, or will not key in properly.

Acrylic paints do not flow as well as cellulose, but the Halfords stuff is a joy to use.

If you have a local vehicle paint stockist nearby, some have the ability to custom mix aerosols - these are far superior to off the shelf sprays (and about twice the price)

Leave the paint to harden for a couple of weeks, then burnish using standard rubbing compound on a damp cloth - T-cut is too gentle for a first cut, follow that up with a good wax polish (Autoglym super resin polish is very good) Be very wary on corners and edges - it is too easy to rub through the top coats back to primer - a full repaint is the only way out then!

I have used this method on all sorts of things, cars, boats (model and full scale) as well as radios and various projects I have built, the end result is directly proportional to the prep time put in, but a glass like finish is very easy to achieve.

Cheers
Sean

[paulsherwin]

Originally Posted by m1ecy

When painiting using any spray method you have to make sure that the paint fully "wets" the surface - too thin a coat will give a patchy "orange peel effect" - you need to apply the paint evenly to a point where the surface begins to shine - the surface has then "wetted".

This is all very well, but with modern acrylic aerosols the difference between wetting the surface so that the paint flows and wetting it so much that it runs is very small. I think this is because so much acrylic volume is needed before it flows properly, unlike cellulose. I've never been able to get this right, and that includes spraying cars etc. as well as old radios

Best regards, Paul

[mickjjo]

I find that when using aerosols that they perform much better after warming them up in a bowl of hot water, It is usually stated on the can that the temperature must not exceed 50 deg C. so if you don't go too high you should be safe. In cooler weather it helps to warm the surface to be sprayed with a hairdryer. .

Regards, Mick.

[Aerodyne]

The warm water trick is a really good one - I should have mentioned it as its a standard with me. Any aerosol will perform badly when cold and far better when warmed up. If you have one that provides only a dribbly, weak and anaemic spray, try the hot water treatment.

Originally Posted by Paulsherwin

the difference between wetting the surface so that the paint flows and wetting it so much that it runs is very small.

Absolutely true, Paul, which is why I only spray horizontal surfaces, turning the cabinet each time so the side, top or front is horizontal to the spray. A slight problem is caused by this, namely the differing distance of the surface from the spray position, but if you start at the furthest and work to the nearest, that should sort it out OK. One further point when working horizontal surfaces is the danger of drips onto the surface, but as long as you keep the head clean and you've warmed up the can and it's working well, that shouldn't cause trouble.
As far as applying clear lacquer top coats (as Sam has mentioned) if you want a really high gloss, its a good idea. I've used it on cars and bikes myself. It provides additional thickness for the final rubbing down, though with radio cabinets I tend not to bother. I usually apply a couple of priming coats, followed by several - say, four to six - coats of top, rubbing down lightly every couple of coats, then finish with fine grade wet/dry paper and Brasso or T-Cut.
-Tony