Viewing 7 posts - 1 through 7 (of 7 total)
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  • #8391
    Dan Walker
    CVRS Member

    I picked up this radio yesterday and I do have the little piece of wood missing on the bottom. It will be recapped soon.
    It is missing the convex oval glass and the size of the glass is 9 3/8″ X 6 7/8″. I did find a supplier for the glass BUT they want $260.00 for one piece of custom made glass, so I will think about that for a while. The cabinet is in good condition and I think it just needs so good clean up. on knob is wrong, so the search starts.
    I do like these Marconi radios

    #8399
    phil
    Forum Participant

    cut a piece of 1/4″ particleboard to the shape of the oval. you can fill the entry cut with epoxy and keep both pieces.
    warm them in the oven. put a thin piece of clear plastic on top of the outside piece. warm it in the oven and when you see it start to droop take it out and push the plug into the middle , that will force it into the shape. trim the excess off later.
    You can get the plastic where they sell lexan and plexiglass. it comes with a protective layer of soft plastic and you can peel that away after the forming. it might be a bubble with a flat front rather than a convex but it’ll look close enough and at least be complete. Of course it’s nicer to get the right glass but I’d just do that for now. I made a few like that and it wasn’t too hard to end up with something acceptable. as I recall I had to adjust my dies a little and make a few until I was happy. the gap and the radius of the curve near the gap you can adjust a little as you go.
    Phil

    you might try to put the inside part down first and push the outside over it. that might make the bubble come out more. I’d just try and see what you get. You might have already made plastic bubbles in this way for other radios? if you don’t have MDF what worked well for me was a scrap of laminate flooring. if the thickness is right you should end up with a flange that you can attach inside the wood box where you cant’ see it.

    #8403
    Dan Walker
    CVRS Member

    Thanks for the reply Phil.. I did buy some of the plastic made for forming with heat.
    I realize that it might take a few trys to get it right.
    Are you sure that I should leave the plastic film on while it is in the oven.
    The guy at the store where I bought it said “peel it off first’.
    I guess I can try it with the plastic on and if it works that way.
    Dan in Calgary

    #8406
    phil
    Forum Participant

    I left it on and it worked fine, when I was done I peeled it off and that made it come out looking perfect.
    before you start cutting the plug you could measure the distance from the inside of the cabinet where the flange will fit to where you want the surface and use the same thickness. I found the kerf of the sawcut left about the right amount of gap. maybe .025″ or so. I used a tiny bit of JB weld to smooth out the cut lines and I rounded the edges of the plug over a bit. Yes I would expect it to take a few tries with minor adjustments to get the correct fit and shape. once you have it you can make as many as you want.
    if the flange is just in the way or too much trouble you could cut it off and just attach it to the sides of the hole but I think you can end up with a flange and then maybe use 4 thumbtacks or if they are too long maybe just a dab of rubber cement to hold it in place.
    you just want the oven warm enough to get the plastic to go droopy , then it;ll form easily You shouldn’t have to push hard or anything.

    I think I’d start by putting both pieces in and let them warm up, then put the plug in the oven wiht the plastic overtop and put the part with the hole on a lower rack to keep it up to temp.
    Once warm youll see the plastic want to droop.do this part quickly before the plastic cools off… take it out and push the outside part down. that way the lens portion isn’t going up against anything that can mark it. It should have some curvature and you want that.

    If you find the plastic gets stuck then you could try at a lower temp or remove it first but I was successful with leaving the film on both sides and I think it might come out a bit more perfect that way. as I recall I might have had to pick some little bits of that surface plastic off the very edges but it wasn’t too bad. if the plastic wrinkles it can kind of get trapped but it didnt’ melt into the lucite or lexan or plexiglass or whatever you call the stuff.

    you have several variables, shape , thickness of your dies, how well they retain heat, how hot the oven is , how long it’s in, how sharp the corners are, how wide the gap is. You might want to adjust things as you go and I’m hoping the results are as good as what I saw. I was quite pleased that it really did come out looking like it belongs there.

    #8417
    Dan Walker
    CVRS Member

    Thanks for the information Phil.
    Attached are some photos showing what I did. and it turned out very good. I used 0.04 thickness as I had quite a span to go across [9 1/2 “] After I cut it out it worked very well,.
    I had the oven set at 210 and it had to be in there about 20 minutes.
    I did take off the plastic covering first , but next time I will leave it on.
    I did a write up of the process on ARF, but here are some photos. Dan in Calgary

    #8434
    phil
    Forum Participant

    I’m pleased that you had some success and it looks great in the pictures. If there is any misfit now you know how you can always adjust the dies. It looks like the curvature came out so well that no one would really notice it wasn’t the original glass and many radios used plastic bubbles. my first attempt was a detrola but that radio was a bit special in that it had motorized tuning. I had a second radio that shared the same die. It must have been one where someone got the chassis and made their own case, even the knobs. they did such a nice job I restored the set and the home made cabinet was a bit of it’s history. anyway it sure beats the pricing you had on the glass one. Nice job Dan.
    Phil

    #8437
    Dan Walker
    CVRS Member

    Here is the radio all finished except for the knobs, which I will do in the spring. The eye tube opens and closes exactly as it should.
    I do like these Marconi radios with the big dial.
    Dan in Calgary

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