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Cabinet and Chassis Restoration and Refinishing For help with cabinet or chassis restoration (non-electrical), please leave a message here. |
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21st Feb 2011, 1:06 am | #1 |
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Advice on scraping a curved cabinet
I'm about to embark on re-finishing the cabinet of a 1933 Philips 634A with its domed top, the classic 'Ovaltiney' set. Is it possible to scrape such a curved area, and what advice would then more experienced members give? I've got a thin straight-sided cabinet scraper but haven't used it before, and I would hate to damage this cabinet in a prominent position by unskilled work.
I propose to refinish the set using Danish Oil which I have used successfully in the past. The front and rear of the cabinet top and sides are stained darker, in a band about 2" wide, and I would obviously like to retain this detail - how should I go about this? Many thanks, Phil
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21st Feb 2011, 10:42 am | #2 |
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Re: Advice on scraping a curved cabinet
I may be mistaken, but assume that the grain runs front to back. If that is so, under no account should you scrape or sand against the grain by following the oval contour of the cabinet, or you'll never get the scratch marks out. You must always scrape or sand with the grain. Most cabinet scrapers are 0.4mm or 0.6mm and a bit too stiff to flex.
Ideally, a thinner flexible scraper would be better to enable it to shape to the contour as you scrape with the grain, so you can cover a wider width with the scraper, but a flat scraper will do the job, a bit at a time. You might actually find that if you apply stripper such as Nitromors, that you can wipe off most of the dissolved varnish with a cloth, then clean off some of the rest with turps on a cloth. It would then perhaps only need a light scraping, then front to back with 360/400 grit wet & dry (used dry) to finish. If you wished to get an even smoother finish, then go to 600 grit. As to the banding, that will originally have been toner, applied with the cabinet masked and toner spreayed on, before the lacquer was applied. The rest of the cabinet will probably have had a lighter shade of toner applied. I don't think you'll be able to re-create that appearance if you intend to use Danish oil, which will penetrate the veneer. Toner isn't a stain - it sits on the veneer. If you try to apply any type of stain, even if you mask off an area, it will soak into the venner, as it is intended to, and will creep along the grain due to capillary attraction. Others may have some ideas as to how you can achieve the results that you desire, but it's important to understand that whilst Danish oil can achieve attractive results, with little skill needed, it makes irrevocable changes to the cabinet as it penetrates into the veneer. The reason that varnish (more likely spray applied lacquer) flakes off old cabinets, is that it was a surface finish, applied over toner, which didn't penetrate the veneer. I'm not sure that these comments will be encouraging news, and others may be able to better advise you how to achieve the appearance that you desire. As to cabinet scrapers, you can get convex and concave curved ones as well as flat, but they're really for spindle work such as scrapping bannisters, chair legs etc, rather than the gradual curves of radio cabinets. Always handy to have a set to hand, preferably the 0.4mm ones rather than 0.6mm as the thinner ones will flex a little. Veritas brand are well regarded, and widely avaiable. EG: http://www.britishhardwoodsonline.co...roducts_id=237 Hope that helps a bit. Best of luck with the project. David. |
22nd Feb 2011, 1:48 pm | #3 |
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Re: Advice on scraping a curved cabinet
Hi David,
Thanks for the advice. You're right, the grain does run from front to back. Actually the lacquer is pretty flaky, so I'll start with wire wool before getting out the scraper. You're right again in that my biggest problem is likely to be in replicating the darker toned bands. The attached thumbnail (with thanks to the Worldwide Vintage Wireless database) shows what needs to be achieved! If I obliterate these, the cabinet will clearly look re-finished, and I would like to maintain the original appearance if at all possible. Unfortunately I don't have access to spray toning equipment. I am therefore thinking of trying masking-off, and using different coloured Danish oils. You can get dark and light ones. To avoid the oil penetrating the veneer and tracking along the grain, spoiling the well-defined line between the two colours, I've come up with the idea of applying a couple of thin coats of light Danish oil over the whole cabinet first, rubbing down smooth and letting it go really hard, then masking off and applying several coats of darker oil to the dark band areas, finally over-coating the central portion with light oil to equalise the thickness of the dark and light coatings. A final top coat or two of light Danish oil over the whole lot should finish the job. If you or anyone else has tried this technique and can report back on its success, I'd really appreciate it! Phil
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22nd Feb 2011, 10:18 pm | #4 |
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Re: Advice on scraping a curved cabinet
I've never tried that myself I think the problem will be preventing 'creep', although the method you suggest may well work, and you've clearly given careful thought to it. Perhaps best to try it on some scrap ply?
One possibility you might like to consider is to replicate as close as possible, the method originally used during manufacture. Namely, to mask off the light areas, and apply a darker colour toner as near to the original colour to the two darker bands, using an aerosol toner, then either applying a lighter coloured toner to the broader lighter area, or it you are happy with the shade of that area as it is, spray the whole cabinet with aerosol pre-cat lacquer. Really, I think the nearest comparison to a radio cabinet such as this, is that of guitars, and perhaps the best source of materials would be a company that supplies finishing materials for guitar makers. You might like to look at this link for some ideas: http://www.behlen.co.uk/Merchant2/me...ory_Code=JETSP I wouldn't want to appear to be diverting you from your suggested approach, just to say that you may have a better chance of achieving as original an appearance as possible by trying to replicate the technique used by the makers, but obviating the need for specialist equipment by using aerosols. The only issue that I have with Danish oil (and wood dyes) is that they penetrate the veneer, then the oil cures, and that is irrevocable, whereas lacquers sit on the veneer and can be later removed or renovated. A nice radio Phil, so whatever finish you chose I'm sure that it will be attractive and that you'll derive much pleasure from it. There are others on the forum who have experience in using toner and lacquer, and might be better able to advise you, and to suggest sources of materials, so hopefully, someone will dive in with some ideas and advice! Best of luck Phil. David |
22nd Feb 2011, 10:33 pm | #5 |
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Re: Advice on scraping a curved cabinet
Hi David,
Thanks once again for the encouragement and advice, and particularly the Behlen products link. You're correct in that I have given a great deal of thought to the best way of renovating a relatively valuable radio. Its monetary value isn't of particular importance as it will remain in my collection or be loaned to the Black Country Museum, but who knows... a future owner in another 78 years might curse "the idiot who covered this rare and valuable radio with Danish Oil!" I'll definitely try the technique on a bit of scrap ply, nothing to lose there and it could well provide valuable experience before tackling the real thing. I've never really liked Bakelite cabinets, but they are starting to appeal to me now - wood cabinets can be really time-consuming! Phil
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23rd Feb 2011, 8:59 am | #6 |
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Re: Advice on scraping a curved cabinet
I think it has all been said, but anything with lines like that must be applied in a lacquer and after the filling and base coats or it will spread through the veneer. Is the current finish beyond help?
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23rd Feb 2011, 4:22 pm | #7 |
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Re: Advice on scraping a curved cabinet
Oh, yes. Most of it has flaked off, including some of the darker toned areas, confirming the earlier assumptions about how the finish was originally created.
Despite my preference for Danish oils, I'm tempted to have a go at masking and spray toning, and try to replicate the original finish by the original means. All I need is a nice dry, warm, still spring day, no interruptions... and deep pockets. It seems possible to spend a fortune on toner aerosols! Phil
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23rd Feb 2011, 5:34 pm | #8 |
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Re: Advice on scraping a curved cabinet
I prefer Morrell's toner aerosols to those of Behlens. I find the latter rather too readily runs and curtains, nor do I care for the colour range. I buy my toners from Restoration Materials at Bury, Lancs and order by telephone 0161 764 2741.
The last time I looked the website wasn't too informative, but you might like to take a peek: www.restoration-materials.co.uk -Tony |
23rd Feb 2011, 5:47 pm | #9 |
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Re: Advice on scraping a curved cabinet
Having just taken a look at the thumbnail pic of the Philips set, I have doubts as to the authenticity of the toned finish, particularly on the cabinet front. I don't believe it enhances the appearance of the set and I'm sure I have seen other sets still with their original finish that did not have that kind of toned pattern. There is an example in my book of one that I believe to be completely original that has no such toning design on the front. Anyone know more about it?
-Tony |
23rd Feb 2011, 8:53 pm | #10 |
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Re: Advice on scraping a curved cabinet
I’ve seen one or two un-restored examples over the years and they’ve all had the dark banding in place. If you look at the pic on page 130 of ‘Radio Radio!’ the banding isn’t present, but the set looks got at - it looks like it’s had the ‘Danish oil’ treatment to ‘do it up’.
If you look at the example at the link below, you will note the following statement: ‘The cabinet has been repolished sympathetically and the set has been overhauled...’ (I suppose it depends upon one’s definition of ‘sympathetic’ but to destroy the original finish and replace it with an entirely different finish, destroying original features would not come within my understanding of ‘sympathy’). The radio belongs to the person who owns it at the time, and it’s there’s to do with what they want, but to be blunt about it, with 'classic' radios - rather than just any old radio - if the owner for the time being doesn’t have the skills to do the work properly, why not entrust it to a professional, rather than make irreversible changes? See: http://www.thevalvepage.com/radios/p.../634a/634a.htm If you look at the image of the one at the link below, the cabinet appears to have escaped unscathed, and you’ll see the banding still in place: See: http://www.marie34.freeserve.co.uk/page2.htm Yet another example refers to the banding at the link below, stating: …. ‘It has lost the bands of stain round the top and sides, but the front has exceptionally nice veneers’… See: http://www.vintageradio.co.uk/htm/sales4.htm It hasn’t ‘lost’ its banding - knobs and backs, and DAC90A mains leads get lost. The banding has been deliberately removed during the ‘restoration’ process at some time during its life. I don’t want to sound as though I’m having a pop at anyone or preachifying, because all of us are on this forum out of a genuine interst in all things vintage, and Phil's original posting shows his own concern to preserve the originality of his set. However, speaking more generally, I do think that when these classic radios – some now approaching 80 years old - come into our possession, we do have something of a responsibility to conserve them. Just my opinion, with which not everyone will agree. I’ve lost count of how many classic radios I’ve seen in National Trust houses of all places, (given that ordinarily, the NT is into conservation and preservation), that on close examination have had all the innards ripped out and a cheap plastic cassette or DVD player shoved in, playing through the speaker. Bizarrely, these radios are roped off and under the watchful eye of attendants so that visitors can't touch them and risk damaging them. Huh? Sorry to waffle on. David Last edited by David G4EBT; 23rd Feb 2011 at 8:55 pm. Reason: Poor spelling! |
23rd Feb 2011, 11:16 pm | #11 |
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Re: Advice on scraping a curved cabinet
I really appreciate everyone's thoughtful comments and advice. I agree with David's views on owners' rights, but the sight of the 'stripped' 634A images that you've unearthed have made me all the more convinced that spray toning and lacquer should be the approach I must take. I saw a nice 634A at last year's NVCF and it was complete with toned bands, which are crucial to the set's appearance. However it remained unsold at £250; a fate which afflicts a lot of restored sets, so I guess most of us prefer a cheaper but untouched example.
However I am still intrigued with the idea of using different coloured Danish oils, which I intend to try on a piece of sanded plywood, and will report back on the success (or otherwise) of this process in due course. I'm just a bit unsure of my own skills with the spray toning and lacquering process, that's all. I've had mixed results with aerosols in the past, and they aren't cheap. This set is becoming a bit like a stately home - a potentially valuable asset, but requiring massive investment first! I've had the set for months and am still working on the chassis, so I'm in no rush. Indeed, Tony's book suggests 'summer' as the best time for spraying, so perhaps I'll procrastinate and put off the job for a few months. For my last major cabinet refinishing job, I took a week off work and I'll probably do the same this time. This weekend I'll remove the Bakelite trim from the cabinet and take some photos to show you the condition of the wood before work starts. Regards to all and thanks again, Phil
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24th Feb 2011, 3:09 pm | #12 |
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Re: Advice on scraping a curved cabinet
For the sake of clarity, I did not intend to suggest that the banding was not an original feature, although I admit that upon re-reading my posting it could be taken that way. My point was that the front panel toning on Phil's set did not look especially attractive (eye of the beholder notwithstanding) and that it might not be 'standard'as I personally have not seen that particular patterning of toner on a 634A. For the record, I would not use Danish oil in any form on a set of such importance as a 634A. I would re-lacquer as close as possible to the original finish, INCLUDING the banding...
Hope that makes clear my thoughts on the subject. -Tony |
24th Feb 2011, 3:17 pm | #13 |
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Re: Advice on scraping a curved cabinet
Having taken yet another look at Phil's set, it seems likely that what I took to be toning is actually the pattern of the grain in the front panel veneer, mirrored in the traditional woodworking way. If so, there is nothing that can be done about it - and it will be unique to that particular set.
Ah well! New glasses will be ready next week, so I'm told by Specsavers. -Tony |
24th Feb 2011, 10:17 pm | #14 |
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Re: Advice on scraping a curved cabinet
Tony,
I've perhaps confused matters, as the thumbnail in post #3 was not of my radio ...it is a picture I found on the internet. I did refer to this in my post with the words "(with thanks to the Worldwide Vintage Wireless database)" My radio is in pretty poor condition and has a much plainer barely visible veneer pattern on the front panel, even plainer than the picture on page 29 of your book. I'll post pictures of the actual cabinet at the weekend. I am grateful for your advice to use Morrells toner aerosols, and I promise not to get Danish Oil anywhere near it - honest, guv! I think I'll post a separate message asking for any pictures of 634As showing the toned banding. At some point I'll have to select a colour anyway, and I'd like to get it approximately right.
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25th Feb 2011, 4:16 pm | #15 |
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Re: Advice on scraping a curved cabinet
No Phil, the confusion is all mine, unfortunately. However, if I'd been right, the picture you 'borrowed' would not have been a good example to copy - but of course I wasn't right! However, I think you'll find that the darker bands around the cabinet will be quite easily replicated with toner.
Morrells clear lacquer is pretty good, too. Costs begin to escalate when you buy toners and such but this set is well worth the expense IMHO. -Tony |
25th Feb 2011, 11:19 pm | #16 |
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Re: Advice on scraping a curved cabinet
Hi Tony,
So, am I right in thinking that what I need is (1) an aerosol can of Morrells clear cellulose lacquer, for the 'light' areas of the cabinet, and (2) an aerosol can of Morrells coloured cellulose lacquer in my choice of colour for the dark bands? I guess 'dark mahogany' would be OK for the latter, but without a colour chart it's hard to know what to choose. I've asked Restoration Materials if they can supply a Morrells colour chart. Would you recommend sanding sealer prior to spraying? Thanks again for all the advice! Phil
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25th Feb 2011, 11:39 pm | #17 | |
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Re: Advice on scraping a curved cabinet
Quote:
Sounds a bit obvious but I had a reaction on the second coat from the same can, the air was so blue the sun nearly came out. |
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26th Feb 2011, 11:09 am | #18 |
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Re: Advice on scraping a curved cabinet
On a previously lacquered cabinet that has been stripped, it should not be necessary to use grain filler or sanding sealer. Choose cellulose sealer if you opt to seal, though a coat or two, lightly applied, of clear lacquer should seal the surface. Look at the coated surface at an oblique angle - low, into the light - to seek voids in the lacquer caused by the grain. If they are there, another fine coat or two should clear the problem.
Don't overdo the coats and try as far as possible to spray on horizontal surfaces by turning the cabinet, perhaps suspended on a board overhanging the bench. I personally quite like dark Oak as I find mahogany to be a little too reddish for my taste. You may well need two cans of clear to do a really effective job. After laying down the sealing coats and lightly de-nibbing the hardened surface with very fine paper, i.e. wet/dry (probably best used dry at this stage) you can mask off and spray the toner in light coats. Spray AWAY from the taped edge to prevent a hard lacquer edge building up. Only do enough to evenly tint the wood. Several light coats are better than lesser heavy ones. Do not overdo the de-nibbling of the toner or you will run the risk of cutting through it, showing the lighter wood. When the toner is hardened off, apply a series of clear coats. Light flatting with wet/dry, used wet with soap as a lubricant, can now be done but remember - caution on the toned areas and all edges. If you use a very fine grade of paper, say 800 or 1000 grade, you could simply buff with T-Cut or Brasso to achieve a lovely soft shine very similar to French polish. Alternatively after flatting, a single final gloss coat of lacquer should look good. TIPS: work on a warm, dry day around noon with workshop or garage door open. Lacquer stinks the place out and doesn't do lungs and brain any favours either. If you see 'bloom' (a dull area) developing in a patch on the drying lacquer, a gentle warm with a hair dryer can drive off the moisture that causes the problem. Great care is needed not to wrinkle the lacquer surface, however. Watch for the aforementioned voids. Recoat and reflat until they have disappeared. If there's black paint needed, such as for feet etc, add this after the spraying is complete. Hope this helps a little. -Tony |
27th Feb 2011, 9:37 pm | #19 |
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Re: Advice on scraping a curved cabinet
Tony, that's fantastic. I'm very grateful for your advice.
Phil
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7th Mar 2011, 11:37 pm | #20 |
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Re: Advice on scraping a curved cabinet
Quick update... the weather was nice today, I had a day off work, so out came the scraper, the 400-grade wet'n'dry, and the grade 00 wire wool. The old lacquer has now all come off nicely. Oddly enough, the domed top was by far the easiest, and the flat front panel the hardest.
Morrells don't do a colour chart, would you believe, so I took some colour photos and Restoration Materials have offered to select the best colours of spray toner and varnish for me. Having removed the bakelite front escutcheon, the toned lacquer finish beneath it was several shades darker than the front panel itself, showing just how much the colour had faded since new. When new, the colour must have been quite dark, and the dark bands darker still. So selecting the new finish colours will be something of a guess. The images below were taken before scraping commenced. I suspect that two tinted toners were used by the manufacturer, one mid-brown shade over the whole cabinet and another darker shade for the two bands. If I use a clear varnish overall, it'll look too light. Does anyone know what the actual wood veneer is? I've read "mahogany" elsewhere, but there are patterns on the front panel that are suggestive of walnut.
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