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-   -   Stove Enamelling (https://www.vintage-radio.net/forum/showthread.php?t=153034)

yesnaby 10th Jan 2019 11:22 pm

Stove Enamelling
 
Does anyone know of anywhere that does stove enamelling? I have some obsolete grill and oven parts for a cooker that were finished in 'polar white'. Lots of places can do powder coating but I don't think that will withstand the temperatures reached without discolouring.

Boater Sam 11th Jan 2019 3:43 am

Re: Stove Enamelling
 
True stove enameling is glass frit sprayed onto metal then fired so it melts and flows.
There are still some firms re-enameling cast iron baths, heaven knows why, but they may help.
Beware, some refinishers think any spray finish on a bath is stove enamel, wrong.

John M0GLN 11th Jan 2019 7:36 am

Re: Stove Enamelling
 
I got a cooker hob stove enameled a few years ago by Trico who did an excellent job.

http://www.trico-ve.co.uk/contract-enamelling/

John

ianm 11th Jan 2019 8:50 am

Re: Stove Enamelling
 
Quote:

Originally Posted by John M0GLN (Post 1109590)
Trico who did an excellent job.

Yes, the original makers of vitreous enamel signs. That sounds like a good idea.

I've recently taken delivery of some custom-made reproduction enamel signs from Trico and I am very impressed by what they can do.

kalee20 11th Jan 2019 12:51 pm

Re: Stove Enamelling
 
That sounds interesting! I have a Tilley searchlight which needs enamelling.

However, it has some parts of the fuel tank soldered together. Does anyone know how hot stove enamelling is stoved at? I don't want a beautiful enamel finish on a set of parts in kit form!

Boater Sam 11th Jan 2019 1:53 pm

Re: Stove Enamelling
 
Too hot for solder, glass melting temperature.

Station X 11th Jan 2019 2:01 pm

Re: Stove Enamelling
 
I don't know about this particular case, but some (not all) fuel tanks in spirit burners etc. were silver soldered as a safety measure lest leaking fuel should catch fire. Mind you I doubt even silver solder could stand up to the temperatures needed to melt glass.

Glowing Bits! 11th Jan 2019 2:38 pm

Re: Stove Enamelling
 
Glass starts melting at 800 centigrade upwards, enamel paint is higher.
If suitable paint was available and the shelves would fit in the kiln, I could fire it all, the kiln goes to 1300C.
Most solder for fusing metal will start creeping at 200C, been there, done that.
Rick.

David G4EBT 11th Jan 2019 3:38 pm

Re: Stove Enamelling
 
Quote:

Originally Posted by yesnaby (Post 1109557)
Does anyone know of anywhere that does stove enamelling? I have some obsolete grill and oven parts for a cooker that were finished in 'polar white'. Lots of places can do powder coating but I don't think that will withstand the temperatures reached without discolouring.

An internet search will reveal many companies who will do stove enamelling and powder coating, but the price is likely to be prohibitive.

It's worth outlining the differences between the three main processes:

Stove enamelling:

In case there's any doubt, 'stove enamelling' doesn't mean 'enamelling for stoves' - 'stoving' is the term for the curing process in an oven at 120 degrees C (248 F), of paint sprayed onto steel with the same sort of spray gun used to spray a car in a garage. Some stove enamelling paints are two-part, but as with cellulose paint, for safety and environmental reasons, have tended to fall out of favour.

Not sure what temperature it will withstand, but presumably at least 120C, and probably more.

Powder Coating:

The powdered paint is electrostatically charged and sprayed onto the part. The part is then placed in an oven where the powder particles melt to form a continuous hard wearing film. The oven is more expensive than a stove enamelling oven because it has to heat the component to a higher temperature - about 200 degrees Celsius (392F). The spray guns are quite different from a paint spraying gun and cost thousands of pounds.

Used extensively for alloy car wheels.

Again, I don't know what upper temperature limit it will withstand, but presumably at least 200C.

Vitreous Enamel:

The key ingredient of vitreous enamel (also called 'porcelain enamel'), is finely ground glass called frit. It's applied by a spray gun, then fired in an oven at between 750 and 850 °C (1,380 and 1,560 °F) to fuse the powdered glass. The powder melts, flows, and then hardens to a smooth, durable vitreous finish. Typical uses are for such things as AGA style cookers, and it was used extensively on gas and electric cooker hobs, splash-backs , doors and side panels, and cast iron baths. Though durable and able to withstand heat, it's main disadvantage, being glass, is that it chips easily if struck by a hard object and can't be satisfactorily repaired. It's a process that's been known about for thousands of years, often used for jewellery.

Hope that's of interest.

Glowing Bits! 11th Jan 2019 3:56 pm

Re: Stove Enamelling
 
Powder coating can withstand extreme temperatures but may become tacky at higher temps.
2k paint can withstand engine cylinder temps without a problem (upto 300C).
Teflon may be a good solution but it's unknown if it's made in any other colour except grey.
Rick.

John M0GLN 11th Jan 2019 4:01 pm

Re: Stove Enamelling
 
Thanks for the explanation of the methods David, my post should have said that I had my hob Vitreous Enameled, there's certainly a significant difference.

John

Ed_Dinning 11th Jan 2019 8:54 pm

Re: Stove Enamelling
 
There were methods for repairing vitreous enamel that used an RF generator and hand held heating coil.
It did a great job on repairing the coatings on domestic appliances that had been damaged during production.

Ed

kalee20 12th Jan 2019 6:07 pm

Re: Stove Enamelling
 
Thanks for the overview of the different techniques David! Very helpful!

yesnaby 14th Jan 2019 10:45 pm

Re: Stove Enamelling
 
Many thanks for the replies and advice, I'm going to search a bit more to see if the parts are really obsolete. If they are I might try Trico as suggested but I fear it will cost too much!

Michael

broadgage 22nd Feb 2019 11:21 am

Re: Stove Enamelling
 
Would DIY be practical ?

My late mother used to make enamelled jewellery and other items and the process was relatively simple.
The article to be treated was rendered very clean by pickling in a dilute acid, and then coated with some form of gum in order that the powdered glass would adhere.
Then fired in a table top kiln, don't know exactly what temperature was used, but it was a dull red heat.

For parts of a stove, a larger kiln would be needed, such as one intended for firing pottery, but the process should be the same.

G6Tanuki 22nd Feb 2019 11:34 am

Re: Stove Enamelling
 
Quote:

Originally Posted by broadgage (Post 1122948)
For parts of a stove, a larger kiln would be needed, such as one intended for firing pottery, but the process should be the same.

That's pretty much how they re-did the parts of a friend's Aga - which was assembled using parts collected from several different dead Agas bought off Ebay. Of course the parts were different colours and chipped/rusted so they were abrasive-blasted back to bare metal and re-enamelled. Even considering the cost of this, the "FrankenAga" still only cost 2/3 what you'd pay for a new one.

Boulevardier 22nd Feb 2019 2:44 pm

Re: Stove Enamelling
 
@David G4EBT - thank you for describing all those techniques - fascinating stuff, and the sort of thing you always wonder about, but never quite get around to investigating. You've just enhanced my life!

Mike

Andrew B 22nd Feb 2019 7:06 pm

Re: Stove Enamelling
 
Aha, I spotted a stove enamalling place in Armytage road, Brighouse, West yorks the other day, if I go past again I'll post the details

Radio Wrangler 22nd Feb 2019 9:16 pm

Re: Stove Enamelling
 
Quote:

Originally Posted by Andrew B (Post 1123064)
Aha, I spotted a stove enamalling place in Armytage road, Brighouse, West yorks the other day, if I go past again I'll post the details

Ah, still there then. I had my AR88 cabinet stoved back in the early 70's by a firm in Brighouse. They were in part of an old mill tat used to be on Bird's Royd Lane.

David


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