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Card back repair and other things

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Card back repair and other things

Post by crackle » Thu Jan 31, 2013 12:14 pm

The repair of this card back was made easier by the fact that the ventilation was achieved by the use of round holes in a regular grid pattern. However it should be possible to use a similar method to the one below with slotted backs, they will just need a lot more work to file the holes to slots. Where the hole pattern is regular concentric circles I would make a template of the hole pattern to mark out the area where new holes need to be drilled.
Philips_206A_back panel.jpg

The problem with this back was that it had multiple areas of weakness and one area in particular, around the largish hole, was crumbling away, it was also very warped. The first job was to try and stabilise the cracked and crumbling areas and for this I used super glue. Super glue is very thin and runny and is absorbed very well into anything porous, it then sets as hard as a rock.
The glue was dribbled around all the holes where the cracks were and on areas where flaking and crumbling was occurring, too much excess was wiped off after about 30 seconds. The back was then crushed as flat as possible between 2 pieces of 15mm melamine faced chipboard with G clamps. I use clear plastic A4 wallets as a barrier to stop the glue from sticking to the boards. After this had set the back was still fairly floppy and weak in other places so I decided to treat it all over to a few coats of PVA glue diluted about 1:1 with water. I went over the both sides of the back with 3 coats of thin PVA to keep the surface wet to help as much as possible to be absorbed. It can help sometimes with the absorption if the surface is roughened a little first. The back was again held as flat as possible between 2 pieces of board weighted with transformers and left for about a week. After a week I removed the weights and top board and pealed the plastic sheet of, this tended to pull a little surface of the back off and next time I do this I should “wax” the plastic sheet. I placed individual transformers at various places on top to keep it flat but allow the air to get to it whilst the card back continued to dry for another week..
When I removed the transformers the back was fairly stiff and nice and flat, but I noticed it started to warp after a while a little so I turned it over and placed weights on it again to allow the other side to air dry a bit more over the next few days.
My original plan to deal with the hole was to cut it rectangular and insert some card of the same thickness. I found 2 pieces of card which if glued together would make the same thickness as the original card back. I went off this idea when I found it too difficult to cut the ragged edges with a knife, and using a file did not feel good on the rest of the back.
I have now used on a few occasions an industrial epoxy “filler” called SPX. This is a 2 part, dark grey, and cream epoxy and came in 2 x 2.5 litre tins. It is extremely versatile and waterproof and has lasted for about 5 years with frequent use from time to time for various repair projects on and off my boat.

I regret not taking more photos of the next stages but I will try and explain them.
I mixed the filler and left it for about 10 min (this one I have is very slow setting) this warms it as it starts to set and allows it to become more runny like treacle. I then wetted all around the edges and up to about 1 inch of the surrounding area of one side of the hole in the card back with the filler and then turned it over onto a sheet of plastic on top of a board so that the inside of the back was facing up.. I then dropped dobs of filler into the area and worked it around with a screw driver to reasonably level and trying to work it into the holes and crevices.
When I thought I had enough depth of filler to fill the area and a good bit of the holes surrounding the damaged bit I placed a layer of woven glass mat over the filler. One piece of about 5 x 4 inches was enough to cover over the edges of the original hole by about ¾ of an inch.
Pressing down gently on the glass tape caused the filler to work its way through the glass mat and a I smeared this around and added a little more filler to make sure all of the glass tape was “wetted” and covered with filler. I placed a plastic sheet over the filler and then a board and used 2 G clamps to squeeze the board and filler. Don’t put the clamps on the centre of the repair area put them around the edges where the original card will help to control the final thickness of the filler when set, some filler squeezed out and I scraped this away.
After 12 hours at room temperature the filler was hard enough to remove the boards and plastic sheet, the result now looked very promising.
back repair 1.jpg

back repair 2.jpg


This is the back of the card and you can just see the outline of the glass tape under the filler.
back repair 3.jpg


Next I had to mark out the holes that had to be drilled and a piece of square acrylic was handy for this, a ruler will also do.
back repair 4.jpg

I wanted to hold the back flat on a board for drilling so I used strips of scrap wood and screwed though existing holes in the back into the backing board. Use a drill stand so you can operate the drill with one hand and hold the work with the other. Check the position of the drill bit in 2 planes so as to ensure it is lined up over the mark where the hole is going. The use of a backing board helped by giving the piece I was drilling some weight and substance to help stop it wondering and vibrating as I drilled, it also helps stop the hole breaking away as the drill goes through the other side. (see later)
back repair 5.jpg

Part way through drilling the holes.
back repair 6.jpg

back repair 7.jpg

The original holes on the inside of the back had a countersunk effect so I went round with a large drill in the chuck and tried to replicate this.
Finished drilling.
back repair 8.jpg
Last edited by crackle on Thu Jan 31, 2013 12:34 pm, edited 5 times in total.

 
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Re: Card back repair and other things

Post by crackle » Thu Jan 31, 2013 1:16 pm

Continued from Post 1

Unclamp and turn over, oh dear, there has been some break away around some holes, there must have been a small gap under the holes which broke away. Time for some super glue to bond up the tatty bits and compress tightly between 2 pieces of plastic and board with G clamps again.
back repair 9.jpg

Excess super glue goes like this in air after a few minutes
back repair 10.jpg

Good and solid now after crushing the semi hard super glue.
back repair 12.jpg

To help hold the back tight against the backing board whilst I drilled some of the holes again to clean them I used 2 screws near where I had to drill again.
back repair 11.jpg


It now just needs sanding both sides with an orbital palm sander.

I tried staining the filler but it was not porous enough to take the stain.
So I went out to buy some paint to cover the grey patch. Finding the right shade was going to be impossible so I selected 2 that I thought I could mix to look right.

I was thinking of creating new labels for the back and these would have been fairly easy to print on to white paper and even distressed a little and stained with “tea” to age them. But the Aerial, Earth, and what was left of Mains Voltage were in silver and this would be impossible for me to easily replicate so I cut pieces of low tack masking tape to protect the printing and painted over them.
I removed the masking tape whilst the paint was drying and tried to blend in the painted edge with a cotton bud.

The finish was too mat and even and looked “too new” so I finished the whole with 2 coats of thinned PVA, from the photos it now looks like it could do with one more coat.
Philips_206A_back panel new.jpg


Note:
If the broken part of the back is still there then I would simply use super glue and compress between plastic sheet and 2 boards.(use PVA to build up and fill small gaps. PVA and super glue work well together, the super glue holds the joint whilst the PVA sets hard.)


Credits and materials used.
glass tape.jpg

glass tape2.jpg

epoxy filler.jpg

Thanks go to the makers of Super glue, (10 x 3g tubes for £1 from a shop with similar name or £3.19 for one 3g tube from our local shop, at that saving it is worth paying a £1 to park in the town.). Thanks also to the makers of PVA and to my other favourite SPX filler.

continued next post.
Attachments
paint pots.jpg

 
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Re: Card back repair and other things

Post by crackle » Thu Jan 31, 2013 1:19 pm

Continued from post 2

Addendum:
Other things repaired with thickened epoxy filler. On this knob from a PYE there was 1/3rd of the edge broken away, you can just see the filler from 7 to 11 o'clock.
PYE knob.jpg

This knob from a KB was fixed by building up the filler around the waxed shaft of the pot.
LR10FM repair knobs.jpg


This is what is used to thicken Epoxy and other fillers.
silica.jpg


Anther more ambitious job for some time in the future, again using thickened epoxy to build up the white side strip and glass tape or aluminium gauss to bridge and strengthen the hole.
Vidor_Gem_damage.jpg


Good luck and have fun
Mike

 
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Re: Card back repair and other things

Post by Red to black » Thu Jan 31, 2013 2:18 pm

Excellent Write up Mike, :thumbl:

Thanks for taking the time to do this very useful and informative thread.

 
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Re: Card back repair and other things

Post by Brianc » Thu Jan 31, 2013 2:34 pm

Thanks very much for the very clear description of the process. I need to get in some of your repair products for future use. One thing this sort of post does it to expand ones area of knowledge about the various products that are available. XPS is a good example of something that is obviously very useful to have around.
Excellent Mike.

 
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Re: Card back repair and other things

Post by Lloyd » Thu Jan 31, 2013 6:54 pm

Excellent job on that back cover, and the knobs too.
I've got an Ekco u29 that's got a big chunk missing from it's back cover, maybe I'll have to give it a go with that filler you have.

Regards,
lloyd.

 
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Re: Card back repair and other things

Post by Katie Bush » Thu Jan 31, 2013 9:46 pm

This has to be worthy of a "Pick Of The Posts" - I reckon :thumbr:

Marion

 
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Re: Card back repair and other things

Post by neil29 » Thu Jan 31, 2013 9:49 pm

Very tidy :thumbl: :D . cheers,Neil.

 
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Re: Card back repair and other things

Post by Refugee » Fri Feb 01, 2013 2:05 am

This thread is is well and truly up to a request for a sticky and Katie Bush is right to ask for Chris to consider it :thumbr:
Broken back panels are a pest when they get bad.
It is a good one :thumbr:

 
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Re: Card back repair and other things

Post by sideband » Fri Feb 01, 2013 11:47 am

Now sticky.



Rich

 
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Re: Card back repair and other things

Post by CTV » Fri Feb 01, 2013 11:49 am

And a POP

 
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Re: Card back repair and other things

Post by Katie Bush » Fri Feb 01, 2013 4:15 pm

oldticktock wrote:And a POP


Nice one Chris :thumbr:

I like creative solutions to problems like this, and Mike is very creative in his approach to such problems, and an amazing number of ways to use our old friend, 'Mr. Glue', whether it be PVA, or Super Glue, or I'm sure, any other kind of adhesive.

Brilliant display of lateral thinking :thumbr:

Marion

 
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Re: Card back repair and other things

Post by IJK2008 » Sat Feb 02, 2013 12:03 am

Mike

That is a brilliant repair on the backboard and thanks for sharing it with us.

Cheers

Ian

 
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Alternate method to make a board

Post by Michael Watterson » Sun Feb 03, 2013 12:10 am

I've had difficulty drilling loads of holes. Bigger boards don't fit on pillar drill and the material needs very well clamped on waste wood, no matter if Hardboard, MDF or card.

I've tried Hardboard and MDF. Plywood is easier, but a lot of work and not very authentic.

I had some old damaged photo mounts and picture mounts / frames and the thick card back is just like some radio backs. It can be bought cheaply cut to size at some photo/picture framing shops.

This is wrecked base with missing part of the Philips 151U

bottom1.jpg


I used it as a guide to mark out a photo-frame type card back. I used big scissors to cut to size and then used water based "varnish" thickly on both sides and dried.

I experimented with drilling ... Messy.

So hit on idea of a Leather punch. I have 3 cheap ones, one is very poor even though looks similar to best one. I used best one around the edge and then took apart the worst one. I found you need paving slab or metal plate, doesn't work cleanly on wood. One thump with ordinary hammer made each hole, faster than drilling. The originals are obviously punched as the effect is nearly identical. Very fast production.

bottom2.jpg

bottom3.jpg

bottom4.jpg


Then I painted it with cheap brown acrylic paint. Big tubes in Mr. Price are 1/2 the price of cheap stuff in Art Shop.

bottom5.jpg




I used coffee tin strips doubled over with holes punched with star head screw driver and riveted on with cheap eyelet kit (now you know where the cheaper poorer punch came from).

bottom6.jpg


There was only two of the large head slotted screws, I put 4 x self tappers till I find some matching type in my many boxes of screws.

 
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Re: Alternate method to make a board

Post by Refugee » Sun Feb 03, 2013 3:17 am

Michael Watterson wrote:One thump with ordinary hammer made each hole, faster than drilling. The originals are obviously punched as the effect is nearly identical. Very fast production.


I bought some of these:-
DSCF6746.JPG


They were from a local flea-market and were about a fiver.
They look like they will produce a slight counter-sink effect like the original panel.
They are made to be bashed with a hammer :thumbr:

 
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Re: Card back repair and other things

Post by Michael Watterson » Sun Feb 03, 2013 3:40 am

:thumbr:
That's what I will look for and possibly get my friend Al to make ones for particular backs. I have lacking any back:
Schneider Romance FM 61
Image
(1958 version shown)

and Siemens Standardsuper E9
Image
I've created a full size paper template by blowing up photo to correct size and using tiled print option

 
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Re: Card back repair and other things

Post by crackle » Sun Feb 03, 2013 11:20 pm

Those punches look the business for punching through card.
Mike

 
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Re: Card back repair and other things

Post by pclover » Wed Feb 20, 2013 10:35 am

Unfortunately those punches soon go blunt and its always the one or two sizes that are most needed.

I didnt find a way of re-grinding them to be as good as new.

Congrats on the fibre glass back repair, excellent result and a clear write up.

Gary

 
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Re: Card back repair and other things

Post by 6.3volts » Sun Apr 21, 2013 12:57 pm

Katie Bush wrote:This has to be worthy of a "Pick Of The Posts" - I reckon :thumbr:

Marion

That gets my vote!

 

Re: Card back repair and other things

Post by Mole42uk » Wed Jul 02, 2014 7:54 pm

If you want to make new backs, you can get the right stuff from: http://www.woolies-trim.co.uk/p-1648-millboard.aspx
It's maybe a bit too thin for some larger backs (my Murphy A188C for example) but could be just right for those smaller jobs.

 
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Re: Card back repair and other things

Post by 6.3volts » Sat Jul 05, 2014 9:51 am

Richard, that looks very useful. Perhaps glueing two or more sheets together with pva (suggestions here please) would produce a stronger material.
Jonathan

 
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Re: Card back repair and other things

Post by Boom » Sat Aug 23, 2014 10:02 pm

That is one nice job.


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