9/16/97
ever clean out their embedding oven? If so, what is used to do this?
I am not so concerned about the cleanliness of the oven, but rather the
problems it seems to be causing when things start sticking to the oven.
There is a plastic petri dish with old desiccant in it that has stuck itself
onto the bottom of the oven, with no way to easily dislodge it.
Any suggestions or comments would be greatly appreciated.
Susan Carbyn
Atlantic Food and Horticulture Research Centre
Agriculture and Agri-Food Canada
Kentville, Nova Scotia B4N 1J5
Canada
Phone (902) 679-5566
Fax (902) 679-2311
E-mail: carbyns@em.agr.ca
clean off the glass door without dissolving my gloves, with limited
success. One day I came into the lab and, lo! the oven was clean. Turns
out someone had cleaned it out with our putty knife WHILE IT WAS HOT!
Duh. She said it was pretty easy. Be careful of all surfaces. Wear
gloves. Worry about toxicity. Disregard me if anyone says this is not
recommended.
http://www.pbrc.hawaii.edu/bemf/microangela
* Tina (Weatherby) Carvalho * tina@pbrc.hawaii.edu *
* Biological Electron Microscope Facility * (808) 956-6251 *
* University of Hawaii at Manoa
a 5 litre three-neck flask that had been used to synthesize alkyd resins -
these are basically phthalic polyesters crosslinked through
polyunsaturated fatty acids. There was a caked-on film that would not
yield to concentrated sulphuric acid, tetrahydrofuran, or any of the usual
things. I put some .880 Ammonia in the bottom of the flask, blocked the
necks with cotton wool, and left it overnight, and next morning the film
had swollen and fallen away and could be yanked out with tongs or
whatever.
Ammonia vapour is very effective with polyester based resins because of
(a) it basic nature and (b) most important, its small molar volume.
If, on the other hand, your resin is an epoxy, it might be better to put a
dish of methylene chloride (dichloromethane) in the bottom, seal the oven,
and go away overnight. Methylene chloride is the basis of most commercial
paint strippers.
The use of vapour technique does make for much less messy operation. Once
the film is loosened, strong detergent should be good enough for
scrubbing.
However, that PLASTIC PETRI DISH would probably turn into a gooey mess
with the methylene chloride vapour, so try the ammonia first. (Also
consider, does your oven seal with an O-ring?)
| Robert H.Olley Phone: |
| J.J.Thomson Physical Laboratory {direct line +44 (0) 118 9318572 |
| University of Reading {University internal extension 7867 |
| Whiteknights Fax +44 (0) 118 9750203 |
| Reading RG6 6AF Email: R.H.Olley@reading.ac.uk |