I know what you're thinking, cleaning your valued record with glue sounds a little on the crazy side, perhaps even an April fools day trick–trust me it's not.
The type of glue needed is PVA which can be bought cheaply from most art or educational shops in gallon cans for about £7.00–10.00 and at time of writing, and is also stocked by UK retail outlet Poundland which sells 500ml for... you guessed it–a quid.
The idea is records are made of vinyl or PVC; so PVA glue won't stick to it instead making a perfect inverse copy of the groove, looking like a reptiles shredded skin
|Note: the thicker part on the right was used to assist peeling from the disc|
The record above was very dirty and covered in mould, so much so it looked like a piece of Stilton cheese on the surface, you wouldn't want to put any stylus though the ordeal of playing it.
A close up shows the grooves in 'negative' with all the dust, mould and other junk is embedded in the dried glue.
Firstly get together all the materials, PVA glue, a small pot (an old yogurt pot is good), possibly a 10mm wide artists brush (not essential) and an old PVC LP sleeve.
Place the PVC record sleeve on a flat surface, put about an egg cup full of PVA glue into the small pot.
Next place the LP onto the PVC sleeve making sure it is level (a spirit level is a good way of checking) as we only want glue on the grooves not the label.
Take the pot of glue and make four small pools of glue at the positions of the clock 9, 12, 3 and 6.
Work the glue into the grooves going with the groove spreading the glue from the outer edge to the run out inner–but not quite up to the label.
You might need to add more glue at different points of the clock, say 7, 11, 2 and 5 and work it in evenly.
The secret is to put the glue on so that you can still see the groove slightly though the white glue I'd estimate about 1-2mm thick and make it evenly spread, I use fingers but you might like to use the 10mm artists brush I mentioned.
I have found that if I make a small bead of thicker glue near the run out it helps to remove it after drying.
The mix must now be left to completely dry which where I live (room temp 18°C) can take 12 hours; the glue is dry when clear–if in doubt leave it!
When it's finally dry use your fingernail to lift the thicker 'bead' area near the run out and slowly ease up the 'skin' from the centre working away to the outer edge trying to keep it in one piece.
Its a long process and will take a day to clean a single LP, but for those rare occasions where mould, ingrained dust or other noise creating undesirables are ruining that treasured LP it does work.
My advice would be to try it on a charity shop junker until you get the feel for the right amount of glue.
In all honesty though the large time spent waiting for the glue to dry makes this impractical for all but a few very dirty records it is interesting though and does seem effective enough when done properly.