Making 'fake' Bakelite parts for restoration - possible?

[martyjames]

I just bought this KRIESLER valve radio. 2 of the Bakelite strips on the speaker grille are missing (see attached photo). I've seen comments it is possible to make 'fake' replacement parts that will match the set (eg stained and lacquered wood strips etc). Does anyone have any thoughts on how realistic this is - I'd love to give it a go.

Second question - does it 'devalue' the radio (not so much monetarily but in terms of its historic value / authenticity) to spray paint a Bakelite radio cabinet?

many thanks

Marty

[Edward Huggins]

IMHO it would devalue a radio to spray paint it. A lot of people are ruining otherwise superb Radiograms thses days by giving them a "Farrow and Ball" shabby chic tratment. As to replacating broken off bakelite parts, much depends on the area of the damage. If small, you can uses exterior woodfiller (Tetrion) and stain it. If larger, balsa (medium density/hard) wood and stain it. Edward

[Nicklyons2]

I wouldn't dream of painting it - originality is all IMHO, especially in external appearance. I've had some success with small cracks/chips in Bakelite using the old, long setting Araldite (now called Araldite Precision in the UK) mixed with a small amount of paint of the correct colour. For bigger parts I'd use 'Millput' of the nearest colour or the white and paint it over befor is sets fully. Being a stiff putty, Millput whill hold a modelled shape until it sets. Alternatively you could make a near approximate copy, let it set then carefully file/sand to shape and then paint.

[Freya]

You might be able to make new bars using this type of product, http://www.ebay.co.uk/itm/1614508851...%3AMEBIDX%3AIT
It cuts well and polishes but may not be the same colour tone.

[Voxophone]

I have a KB BM20 needing a replacement vane in the rear grille. I haven't taken the plunge yet, but I found that this thread gives good advice: https://www.vintage-radio.net/forum/...ead.php?t=9026

Liam

[Robert Darwent]

Originally Posted by martyjames

I just bought this KRIESLER valve radio. 2 of the bakelite strips on the speaker grille are missing (see attached photo). Ive seen comments it is possible to make 'fake' replacement parts that will match the set (eg stained and laquered wood strips etc). Does anyone have any thoughts on how realistic this is - i'd love to give it a go.

I did this sort of thing to an Ekco AD75 a few years ago now - details of the restoration are to be found here: http://www.wavesintheair.co.uk/ad75.html

Hope it gives you some pointers on how to proceed with your Kriesler.

Regards

[mark pirate]

I certainly would not dream of painting it
It should not be to hard to make replacement bars, you could make a mould from one of the others. I have used fibreglass resin to replace broken sections of Bakelite, it is strong and easy to work with.

Mark

[martyjames]

Very helpful information - thanks everyone, much appreciated. I think i'll firstly try the balsa wood method - Robert Darwent's Ekco AD75 spar fabrication method should be similar to what i need to do.

Thanks again

[Scimitar]

The fibreglass mould idea is the best, because you can replicate the good bars exactly. The resin can be pigmented when mixed or painted afterwards to match. It should make an invisible repair.

[martyjames]

Hi Scimitar, how would I make a mould if I don't have the broken pieces? Would I have to cut one of the bars out of the radio, make a mould of it, and then glue it back in?

[Lloyd 1985]

You can do what I did to my Ekco AC76, you get the silicon moulding compound, and make a mould of an undamaged part, look at the front of your radio, all the speaker bars are the same, or at least very similar to each other, once your mould has set you then remove it and place it where the broken bar is (I'd do them one at a time) and then add your resin of choice where the missing bar is. Once the resin has set, you remove your mould and your replacement speaker bar should be identical to the others! If you added some pigment to the resin, then you are finished, and can move on to the next one, if you didn't then you have to get creative with some paint on just the speaker bar, not the entire cabinet!

You don't need to cut out one of the bars to do this, just place the radio face down, make a little cardboard box and tape it to the front of the radio and pour in your moulding liquid, unless using some sort of moulding paste or putty that isn't runny like the stuff I use.

Here's some shots of my Ekco, Ok it's not making a complete replacement part, but you can use this idea to do that too. the end result looks quite visible in the photo's, but once the whole area is polished up it'll be less noticeable. I actually have another of these sets now with that front part undamaged, so I intend to make a mould of the complete front part and then transfer it to this one!

Regards,
Lloyd.

[martyjames]

Hi Llyod - very interesting and impressive what you did (as an aside i saw an Ekco on ebay a few days ago but it sold for way above what i could pay! - amazing radios!). I have no experience at all will making mouldings but just did a search and moulding mix can be purchased locally, so i will definitely consider it if the balsa wood option doesnt work out.

I totally disassembled the radio today - its 100% original, full of dust. Ive cleaned it out and brasso'd the case and polished it and its come up nice - so making the broken bar is next along with replacing the speaker cloth (which is hard to source locally , so it might be ebay for that)

Thanks again

Marty

[Scimitar]

It is fairly straight forward Marty, no damage to the originals at all. You clean and polish one of the other bars to act as a master. Polishing is to ensure that the mould releases. You will need to remove the grille cloth and replace it with around the master bar with some stiff card etc, covered with resin proof tape.

Now you cover the bar and card with two coats of fibreglass resin, allowing them to go off before doing two more. Now mix some more resin and cut pieces of fibreglass tissue and stipple these onto the next coat of wet resin. A couple of layers will be adequate. Then once gone off, you can use fibreglass matting to build up the mould, again no more than two or three layers at a time. Make sure that all the air is being pushed out of the laminate, or the mould will be weak. Once the job has gone off for a week or two, you can carefully remove your mould which will be a stable negative copy of a good bar.

Making new bars is exactly the same as making the mould, but make sure you polish the mould properly, or the new bars will stick to it. This mix of resin could be pigmented if you wish. Remove the replacement bars from the mould once properly gone off and clean them up. You can make as many as you wish now, maybe sell some too. ;-)

Now you can do what you wish with the new bars. I would clean up the ends of the broken bars and cut the replacements to match. Try your resin to join them, otherwise an epoxy resin might be required.


Important... Before you do anything, practice on something else, to get the feel of it before the real thing. Describing the job sounds more complicated than it really is, so don't be put off. There are many useful guides out there about the multiple uses for fibreglass. Quality of materials is very important, don't be tempted by a "Boy's own fibreglass kit" in your local shop, get everything from a trade supplier as the kits are frustrating even for the experienced user. The trade supplier will also be able to advise you of course.

[Scimitar]

Lloyd's suggestion for fitting the mould is a very good one, if doing one at a time. The only thing to worry about there, is if the original broken bar will not take the resin. If that is the case, you can get epoxy based fibreglass resin to sort the problem.

[martyjames]

Excellent -many thanks for the detailed explanation Scimitar - i agree, its a matter of giving it a go and having a practice run on something else first. I'll do some research on materials for both methods tomorrow

cheers

[petervk2mlg]

These are such common radios that I wouldn't spend too much time and effort on repairing it.
A good one will easily come your way if you keep any eye out.
That said, there is a quality Bakelite restorer in Sydney who could help you out.

Peter

[martyjames]

But the enjoyment is in making it good Peter!

I've made 2 trial missing 'spars' today, the case is polished and new speaker cloth on the way, so it will look great when finished hopefully!

[G6Tanuki]

I'm thinking that remaking these parts would be an ideal application of some 3D imaging/printing.

A 3D imager could non-intrusively map the contours of one of the unbroken Bakelite strips and then a 3D printer could produce - in an appropriately-hard plastic (though not necessarily the right colour) - a copy.

A friend has just had some black plastic switch-toggles for his 1960s Italian car 3D-printed. Perfectly-functional and only £10 - a bargain! "New-old-stock" versions are over £400 each!