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Groggy
14th August 2011, 03:32 PM
I have been asked to fix a chair for a friend. Once disassembled I noticed that the timber is very light and the mortise and tenon joins have been put together with silastic! The trouble is that to get a good join with an epoxy I need clean surfaces and the silastic has gone everywhere.

I've got the tenons cleaned up but the mortises are more of a challenge. Any ideas on the best way to go about it? If I use a chisel I just get smooth silastic sides to the mortise. I am thinking of a dowel in a drill with a bit of sandpaper wrapped around the end (in a split).

Stringy
14th August 2011, 07:43 PM
Petrol works well for removing silicone, but the chair may smell a bit dodgy for many years, acetone should do the same without the lingering smell and flamability:D!

Master Splinter
14th August 2011, 07:49 PM
:iagree:

Groggy
14th August 2011, 08:15 PM
Thanks guys, I'll give acetone a go. :2tsup:

mic-d
14th August 2011, 08:24 PM
Acetone won't touch it I'm afraid. You can buy silicone remover which is gellified sulphuric acid, but I can't say how that would affect glue up. How about mark cuts for new mortise sides, chisel and remove and glue appropriate thickness veneers slips to the tenon? :shrug:

issatree
14th August 2011, 08:29 PM
Hi Groggy,
I bought some " Mostenbockers Lift Offe " Silicone Latex Caulk & Foam Sealant Remover. 125ml.
How ever I haven't got to use it yet, so I don't know how good it is. Was bought to do the Shower Base, but I was advised, that this is the Stuff. Bunny's $14 +.

BobL
14th August 2011, 09:11 PM
Acetic acid also works. Ordinary table vinegar (4-8% Acetic) is not usually strong enough and high strength spirit vinegar at about 15% - 20% is required.
One advantage of acetic over petrol is that it washes off reasonably well.

Groggy
14th August 2011, 09:33 PM
Yuck. From what I am reading I may as well just bevel the sides of the mortises and use fox tenons.

Fancy using silastic :(

Pops
15th August 2011, 11:37 AM
Hi Groggy,

I think you are on the right track. Had a similar problem with an old window frame. Tried sanding the stuff off, whicj I thought was OK, but when I ran my hand over the timber it still felt silicon slippery. The stuff had got into the weathered cracks, arrhhhh!!!.

Had to cut a bigger rebate to expose new uncontaminated wood.

Silastic great for gutters, but a pain for timber. :)

Let us know how you get on witht eh mechanical type fix.

Cheers
Pops

rogerjenkins
15th August 2011, 09:25 PM
Turpentine also works. Lay chair sections on their sides with the silastic filled holes facing upwards, and fill with turps, and allow the silastic to soften. takes a while, but does S-L-O-W-L-Y disolve the problem. Another option is Paint Remover, or even Universal Lacquer Thinner

Been there,- done that:!. Had that headache:! Done a bit of Furniture Restoration work over the years.
It never ceases to amaze me what some people will use to, " Glue," a loose dowel, or rung back into the chair with. Liquid Nails, or Construction Adhesive is another favourite product many people use to re-glue chairs, tables, cupboards, etc, or you get the occasional person who uses a, " six inch nail," bashed right through the joint to try to hold things together, or occasionally the old farmer who believes that a piece of fencing wire and a pair of pliers will fix anything :U:U ( Well almost anything )

Roger

Groggy
15th August 2011, 11:09 PM
Oh, these chairs have not been previously repaired, that is how they were MADE! :doh: