Speaker Grill Cloth fixing question

[SurreyNick]

I am thinking about how best to affix the new speaker cloth to the Marconiphone 55 and because I have never before tackled this task I hope I can get some suggestions on the best approach to take.

As you can probably see from picture 1 below, the old speaker cloth was beyond salvaging. It had perished in several places and was so threadbare it was coming apart. Parts of the cloth was stuck directly to the wood of the cabinet in places, but I don't know if this was by design or accident, because in other places it was loose, resulting in a disheveled appearance. Do you think it would have been glued directly to the cabinet so as to be nice and tight? If so, what is the method to get the best result?

If you look again at the picture you can see that a narrow cork strip 1/4" wide was pinned and glued to the cabinet in a circle the same diameter as the speaker cone. Then as you can see from picture 2 the speaker grill cloth was glued to the inside edge of this and a strip of felt the same width as the cork was glued on top. The rim of the speaker cone sat on top this felt. The cork and felt was also beyond saving, so I have bought new. I just need to know how to get the best result with the grill cloth.

Can anyone help?

Thanks

Nick
           

[Radio Fixer]

Its tricky Nick.  I have done many and still mess up so first tip have a spare piece of cloth.  The best cloth for a beginner is one without lines as in mags you will see lots of pics of radios where they aren't straight.  Yours looks good as it doesn't seem to have a strong  pattern.

It is always easier if the radio has a baffle board as the cloth can be stretched out, after ironing, face downwards on a flat surface.  I use a surplus piece of worktop and helped by my wife we tape it down with tension along warp and weft.  Doing it like this it can be checked (and checked and ch...)  and I use a ruler if the cloth has lines.   Then the baffle board can be sprayed with 3M adhesive and lowered in place and then weighted.

I will post a PDF article of how I did it for a Gecophone speaker that didn't have a baffle board.  As you will see I used UHU adhesive, which is transparent and works but is messy but only to you.  You may do better to go to a craft shop and ask for Material Glue.  This is normally latex and should be cleaner but will it have enough 'grab' of the cloth.  Something you would need to have a dummy run on with a piece of scrap and a board.

Trying to glue it in place in one hit is a sure way to a messy failure to me.


  The_Bulletin_2012_1_Stork_Article.pdf (Size: 1.79 MB / Downloads: 31)



Gary

[SurreyNick]

That's a lovely job you did with the speaker cloth on 'Storkie' Gary. I will follow your advice and glue it in stages. Sadly (stupidly) I only bought one piece of cloth and it has a herringbone pattern too! I'll have to be extra careful and keep my fingers crossed. I have some UHU so that's what I will go with.

Interestingly, in your article (nicely written by the way) your cone speaker is held in place in the cabinet with wood toggles and that makes a lot of sense. There was nothing like this holding the speaker in the Marconiphone, it was supported just by the steel pin which connects to the cone from the magnet leaf. I am now wondering if these toggles would have originally been there and have been lost in decades past. In which case I will want to replace them.

Nick

[Yorkie]

I think that given the age of the set, originally the fabric was most likely stuck with animal glue, as no doubt the cabinet would have been.  The best product I've found for fixing speaker fabric is an aerosol spray aptly named ‘STUK’ rapid spray fabric adhesive. It’s colourless and comes in a 500 mL aerosol can with a nozzle to adjust the rate of delivery from low to high. You spray the board – not the fabric, and although it has excellent ‘grab’ it does allow you time to stretch the material taut and to adjust the horizontal and vertical patterning of the fabric so that it looks just right. A can lasts for yonks. You can get it here:

http://www.ebay.co.uk/itm/STUK-Rapid-Spray-Adhesive-Glue-Carpet-Etc-500ml/371182119175?_trksid=p2047675.c100011.m1850&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D1%26asc%3D33842%26meid%3Df7dce5d59c604791ba661de7ba782278%26pid%3D100011%26rk%3D2%26rkt%3D10%26sd%3D390437256870

I've attached a pic of the can, and a close-up of the adjustable nozzle.

Sometimes I spray it into a container and apply it with a coffee stirrer stick to stop it going all over the place.

If circumstances permit, if the original was held down with staples, I shoot a few staples in.

Hope that helps a bit.

Good luck with the restoration Nick.

[Radio Fixer]

David's way is doing it in one hit which I have never tried. I have seen one result of someone who had and it was not taut and he had got adhesive on the front face of the cloth. Easy to do as you lower the piece into place and try to say fix and stretch out the top. The rest of it and not taut is draped on the adhesive covered surface.

I should have said a little more about the choice of cloth: obviously no distinct pattern is easier but also the weight of cloth is important. Much I have used has been proper repro speaker cloth whereas some sold is just off cuts of possibly curtain or upholstery fabric. This is not intended to have any stretch as you don't want to keep shortening curtains. Whatever material you have after ironing lay it on a clean surface and try just gently stretching it out with your fingers, in both directions. If it is really stiff then it isn't IMO suitable. Find something else. If it moves under gentle pressure just get the feel of it in both directions. You certainly need a little stretch as without it it will sag ... I have been there. Spraying with water and drying usually is a failure although you will find some who say it works. IMHO the reason it doesn't is that modern fabrics are petro based and designed not to shrink anyway.

I would fix the top trying to smooth it out evenly with a degree of stretch you will have to guess but I have a feel for it now. When dry you can turn the cabinet around and let it hang down and see if its looking good !! Then, me being right handed, I would do the left side and check as before. If all still looking good then go for the right side and bottom in one go, the only way.

David's adhesive may be better possibly applied by brush. I certainly wouldn't spray the whole surface and if it has bars or fretwork then no way. I have used my way of doing it on several radios including Bakelite where I used Evo Stick.

On baffle boards this is the glue I use:http://www.amazon.co.uk/dp/B000NJZXHS/ref=sr_ph?ie=UTF8&qid=1445013337&sr=1&keywords=3m+spray+adhesive

They all say "clear and non staining" but I don't trust that. To the critical eye, get it on the front and it can be seen, often not at first but months or years later, odd that. I trust 3M products having used them for photo mount for years.

Good luck with it.

Gary

[Radio Fixer]

As I was standing in the queue at the Chipie (busy night Fridays) I thought why glue on the front may not show up at first.  Perhaps it seals the cloth and when the cloth fades a little then those parts stand out.  My philosophy is just don't get it on the front in the first place.

When you have the top and later one  side in place you can always get a helper to look at the progress from the front whilst you position the cloth before the next adhesive.  A large mirror may work for you but not for me.

Here's a Bakelite one done years ago and the cloth still just nicely firm to a light touch.

   

Of course I expect you will sand off all the old animal glue first.

Gary

[Joe]

I think there'll be as many ways of doing this as there are people doing it.

The only one I've done which didn't have a baffle-board was a Pye MM.  I ran a bead of hot-melt glue along the top of the front board above the opening and the placed the cloth onto that.  I then ran over it with an iron to re-melt the glue and get it right into the fabric.

I then ran bead down the first couple of inches of the fretwork and did the same again pulling the cloth tight until the glue had cooled and repeated this until the job was done.



— Joe

[pwdrive]

Looking at the pics it's hard for me to see the total area of the board at the back, anyways looking at the pics how's about this for a trick, just an idea, might or might not work but I bet I could do it.


Remove cork/felt ring etc so's you have a bare board, use a compass to draw a circle, the perimeter of which will define the available gluing area between the said circle and the edge of the cut outs, that area plus any other suitable areas on the fret work bits is where to put the glue, but not yet.

Take a couple of square sticks say 12 mm x 12 mm, cut the cloth plenty long enough and wide enough to suit, staple one end of the cloth along one stick and the other end along the other stick then roll the cloth onto the sticks by rotating the sticks, when the distance between the two sticks with the cloth wound round them approaches the diameter of the compass circle stop winding the cloth on, then cut a couple of more sticks to use as spreaders, cut them a bit longer than the distance between the two sticks the cloth is wound on then use them as spreaders to make the cloth tight and even, some thin sheet bits of plastic or stiff cardboard will be needed to put between the end of the spreader sticks and the cloth that is wound on the sticks you are spreading to stop the spreaders binding on the cloth, in other words your starting with spreader sticks that a slightly too long when the cloth is not tight, the sticks are dropped in at an angle to get them in then spragged out so in effect you end up with a square frame with the cloth tight on it, once that is done then glue or tack a couple of thin bits of timber/hardboard etc across the corners to keep everything in it's place, when everything is tight and non wavy apply the glue to the glueing areas and drop the whole assembly on it, you might have to apply a bit of pressure to the back of the cloth where it's glueing, you might be able to use your fingers to make sure the cloth is making contact at all points, once set then remove the timber/hardboard corner pieces and the two spreader sticks then unwind the other two sticks from the spare cloth, cut round the compass line with a sharp blade to remove all the spare cloth, re do the cork and felt and that's it.

Might take a bit of trial and error using the spreader sticks etc and you might have to stop them springing out until you get the corner pieces tacked on.

It sounds complex but I don't think it would be once you've worked it out, hopefully you will get the general idea from the above description, if not I'll scribble up a drawing and post it up but bear in mind it's late for me now tonight and I'm down the woods again tomorrow until late afternoon.

This has been another idea from the House of Lorenzo

Lawrence.

[pwdrive]

I've had my snooze, it's early A.M. I wake up early if I've got a pile of work to do like down the woods, I've just finished sharpening my chainsaw, anyways further to post #8....an improvement for the stretchers, maybe two lengths of threaded rod, 4 nuts and washers, needs no explanation, it should work ok, fiddle, experiment, adapt etc...don't give up on doing a first class job.

Lawrence.

[Radio Fixer]

"I think there'll be as many ways of doing this as there are people doing it."

I don't think that's quite true Joe ... there are really only a few ways to do it.  Yours is an interesting variant of mine.  However, I'm not sure how you stretch the cloth out when you iron the top and eventually the sides. Hot melt glue hurts fingers pretty bad    Without stretch, with the materials I have used, they will sag.  Perhaps with curtain material it wouldn't as that stuff has virtually no stretch anyway.  Did you glue anywhere to the fretwork?  I normally don't do this except in the Stork speaker case where the front slopes and the original was done this way. The reason for not gluing to the fret is that I have seen cases where the cloth has sagged in pockets between the fret cut out. Without the glue there is a chance that those sags would have evened out across the whole front. And you have the last ditch of 'spritzing' and drying it to tighten.

Lawrence's proposed method seems to be a variant, for direct to cabinet, on the embroidery hoop that I have read of people using when the radio has a baffle board.  But to me the method I gave for this is tried and tested and better than several other ways I have used.  

I doubt I would have had room for the sticks inside some cabinets and to me its untried and tested.  To say "fiddle and experiment etc" is OK if you have a limitless supply of cloth but the stuff I buy is normally expensive, is posted from overseas (the speaker one was from the US and the Volks from Germany) so I wouldn't want to waste it.

I reckon I get a first class job doing it in a simpler fashion.

Gary