Cabinet Parts - Moulded Replicas
Dear Radio friends,
Often in Portugal-Lisbon we have some radios to restore and no components to replace.
That’s why a Portuguese team composed by Jose Costa, Julio Branco and I, have tried to manufacture some components.
Of course we don’t dare to make vacuum tubes, as one can see on the video at Leonardo Mureddu's Forum. We have tried to replicate only some of the easiest components, like knobs and other moulding stuff.
I think we had some success with the transparent Philips knobs project.
Encouraged by these good results we went forward and we tried to replicate a Pilot 203’s rear cover. What a task! ( Pilot 203 on http://www.radiomuseum.org/r/pilot_203_2.html )
This is a very large component (237x320mm), so the difficulties increased too much during all process.
DOUBLE SILICONE RUBBER MOULD
REAR COVER REPLICA (front a back sides)
Further retouches had to be done , because some bubbles insisted to appear. A vacuum camera should be the solution, but only a very large one.
Also, here moulding materials are not easily available. We had to use resins and a catalyser without any commercial reference.
Any of you have already tried to mould plastics? Do you know any Brand here in Europe or where these materials are available?
Thank you in advance for any information about this subject.
Dear Radio friends,
I believe that in Rmorg there is somebody who have already tried to mould plastics.
We think that Urethane RTV and a slow hardener Epoxy resin can be purchased, even in
Do you know where I can command these products in
On the other hand there are quite different small makers around - also in your country. They have sources for different materials including colors. For the vacuum: Already big glass bowls and a cheap water pump will improove tremendous.
Dear Radio friends,
Thank you for your kind reply,
I did not get in my country yet an alternative epoxy resin’s supplier .Then I'm going on with some more experiments with the same materials.
This time, I have made a series of 6 transparent knobs. They have no bubbles, even without using a vacuum camera, because the moulding process was much better improved. I have increased the number of air outlets, and I have created a higher feeder to make some pressure inside of a stanching mould.
After a week of cure under sun light all knobs were ready to be mounted on a radio set. This seems to be the secret for this material. We cannot touch it for 7 days because the finger prints become visible on its surface. It is ready only after 7 days. We are always learning. :-)
Thank you for your attention,
I would like to show you some replicas of knobs made of epoxy resin.
Thank you for your attention,
Thank you for sharing this.
Aos Amigos artífices dos botões
Parabéns pelo Vosso trabalho exemplar.
A Vossa iniciativa é prova de que a necessidade aguça o engenho e quando um Homem quer e com a sorte de Deus a Obra aparece.
Porque o nosso mercado ( Portugal ) é pequeno na generalidade e muito mais na área das tecnologias, as coisas não existem ao virar da esquina e por vezes temos que inventar, improvisar e fazer ou … importar .
Mas parece que não são os únicos a fazer botões, pois vi uns semelhante expostos na Radiolux 213469327, serão os vossos!
Muito Bem Haja a Todos.
To the Friends craftsmen of the buttons
Congratulations for Your exemplary work.
Your initiative is test of that, the necessity stimulate the wit and when a Man wants and with the luck of God the Workmanship appears.
Because our market (
But it seems that are not the only ones to make buttons, therefore I see displayed some similar in the Radiolux , Lisbon 213469327, will be yours!
Very It Has Well to All.
Estimado Mário Bermejo,
If you want to, we can replicate your Zenith's knob. We shall be very pleased to help you. Send me the original one.
I do not want to keep me at silence on this subject, and present of great steps given for ours countrymen’s . I leave here mine contribution I hope it valid.
I recently get in the Ebay a RF generator the HP8640B, after one trouble trip of England for Portugal, arrived a little injure, it have many problems one of them was a dentated wheel that had disappeared, mechanism of the modulation in FM.
I decided to make one replica of another existing, a new wheel is only possible by in a large market in USA, or one another used but the price is near a of a new, with the knowledge of the existence of a teem of countrymen that made buttons replica, between them was the Mário Coelho and Jose Duarte (They have Well) the Mário send me the contact of the seller of inks and products for moulds in the street of Madalena in Lisbon.
I had start march by my foot and resulted is this:
This is the HP8640B bad shape
This is the damaged device in exterior of the big machine, it had an dentated plastic wheel (selected in the photo) broken and cracking and that will served the matrix, involves a brass centre and that wheel in a steel came in a distinguishing system.
The core brasses are irregular surface not allowing the insert in plastics for simple pressure.
The dentate wheel broken/crack was removed of the brass nucleus in two parts, and with cinolite glue restored and clean, this served of matrix for the moulds in liquids rubber, the matrix was suspended in a cup and the rubber drop in the that cup later gone the vacuum chamber.
The amounts of the base liquids rubber and its activator and later the resin crystal and its activator had been rate 2% and 5% for each cases.
With syringe therefore the weights in mine in that case they were in order of few gram, are necessary to measure the little amounts with accuracy ,
not to lack and not to waste very material, but is desire to exceed of material than the material lack
The activated time is more than one day for the liquids rubber, forgets the moulds during a weekend (depending the temperature )
The astonishment is the precision of the moulds, the demoulds of the rubber is likeable, but only after cure testing with your finger if not glue it is good.
In these moulds I drop the crystal resin later to get the final parts.
The part A It is the glue dentate wheel and that it served of matrix, it´s need inserted the brass core hot (delicate process made with control of temperature of the iron to weld) in centre of plastic wheel.
The part B was the first attempt of experiment , is possible to give to colour the resin but this to use proper pigments in the same seller in street of Madalena, other inks do not attach with resin and are like soup deficiently mix, in mine the case the inks had for seating in the deep !. The resin need many time (hours) to activate (to make solid), but just is sticky to a finger touch and stay stamp is there, is strong like bakelite but broken like glass. To complete dry need a week!!
The part C the end, was more elaborated therefore I had to produce two holes in inside diagonal lines to be able to press 2 screw ( inside hexagonal)
in the brass core these almost micrometric and worst is in inch (who to know of these tools 3/64" e 4/64" tell me, I am thankful), the hole of brass core must be aligned with hole of moulds, thing of patience.
To drop the resin is in this case it’s like a cast method therefore in the first attempt I got air bubbles that invalid purpose of the wheel, not work in distinguishing system.
Start again with resource the chamber of vacuum and work of watchmaker or silversmith (with a needle remove the big bubbles) I made with that, no more exist the air bubbles in the part.
Finally the final assembly
The part D is the glue and original part and the E is the replica
Here in great plan
After that and other interventions the HP8640B already it sing high and in many tone.
It is my experience with the moulds here, I agree with Mário Coelho exists little information on this product, as for example to modify the times reaction and as to modify the texture of the same
In the Internet I found sites where seller this products for moulds and one with small videos who describe exactly of as making, I send us a Email but they wanted to vender in amount, like boxes.
To finish, already after this I tried to make a knob of same HP the things lack and had complicated due to missing brass nucleus with two punctures in diagonal line and with core is very slim, and the restore is in this device not the goal but yes functioning I opted to using one another button of different aspect.
This is part I …
Very Has Well to All
Hernâni Capela (Chapel)
Recently I have bought (cheap) an Philips 2514 in not so good condition. The right "Philite" side-plate was missing. I have no possibility to make the mould. Can anybody help me to find this part???
Thanks a lot,