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sealing oil lamps or the secret of amber varnish

updated wed 28 feb 01


Khaimraj Seepersad on tue 27 feb 01

Hello to All ,

Logan ,
[ you have to use a drying oil - Linseed is your best bet ].

You can try this -

Buy some linseed oil [ alkali processed ] and soak your lamp
in it , leave it to dry . May take days , so put in in the sun .

Take the linseed put it in a long shallow tray , and pour a thin
coat oil [ 1/4 inch deep ] and expose to the sun for about 3 to
6 weeks . Stir every day . After a few weeks the oil will become
very thick like cold honey .[ at the last stage stir 3 or more times
daily ].

Cover with a glass elevated off of the tray with cork or stones ,
but leave about 1/2 " to 1" space for air to reach the oil.
When a drop of this Sun - Thickened Linseed oil can dry over
night on glass , your ready .

Thin the thickened stuff with a solvent , turps or mineral spirits .
Apply to your object , leave to dry .

Or you can buy some Copal Resin or Amber and heat to melting
point - about 300 deg.c and when melted , take off of the fire [ a
kitchen stove cannot do this ] and add in linseed oil [ alkali refined]
to make 35 % Copal / Amber Colophony [ Copal or Amber melted
or " run " as they say is not a resin , but colophony ] to 65 % Oil.

Thin using solvents as needed or if needed apply - takes at least
2 day at full sun exposure to dry .

Or you can try taking a hot oil lamp an rubbing dammar resin or
mastic resin all over the pot , but this may end up sticky .

There are also liquid driers that will speed up drying , but all are
handle with care TOXIC !!! - cobalt , manganese TOXIC !!! are
the faster driers .Only a drop needed .

Or you could try a water based urethane .

What about soaking in liquid wax , something harder than bees
wax ?

Down here they do use normal polyurethane on low fired earthenware
, but never to hold oil . Just for decoration .

Wouldn't it simpler to use Stoneware or Porcelain fired to the vitreous
state ? or a vitrifying Earthenware ???
These don't seem to be very professional finishes ?

-----Original Message-----
From: Logan Oplinger
Date: 27 February 2001 4:58
Subject: Re: Sealing Oil Lamps

>Vince and Others,
>In following this thread on oil lamps, I remember that somewhere in my
reading about the production of earthenware cookware, it was stated that in
order to seal the porous clay, various plant resins would be applied to the
fired clay, and the clay then heated to a temperature that would dry and
permanently set the resin to seal the clay.
>I am wondering if anyone has considered the the possibility of coating the
inside of the fired lamps with a heavy vegetable oil, then baking the lamps
in an oven to about 400-450 deg. F. to carbonize the veg. oil. It may be
necessary to repeat the process two or three times. I know this works on
frying pans and baking pans, but will it work on earthenware?
>Logan Oplinger