gesso as barier

Seals are a very big problem here in Oregon. We would be more than happy to give you about 5,000 Harbor Seals that are decimating the Salmon stock.

Rabbits and Seals generally are not seen in the same arena... as the rabbit either drowns or the seal dehydrates. That's why you don't usually see rabbits cover with seals in gesso coats.....

As for cross-species breeding.... the neo-cons won't let us address that subject outside of Oregon.

And that person with the persistent delusion makes about as much sense... unless they are either first priming the rabbit with Lineco barrier tape, or finish the gesso with a layer of metal leaf.In which cases, gesso works. :D

And while we are on such a serious note: Your Logon.. Penquin with Dark Glasses....
Could that be a Nun with a dark perspective?
Someone I know lives with the persistent delusion that gesso can be used to seal the rabbit of a frame. Is this a common myth? Not in this part of the woods. I've never heard that before. Is there anything to it? I wouldn't think so. Is there anything in the world more porous than gesso?

Baer, are you making fun of Penguin's spelling? 'Cause that would strike me as ironnick.

[ 08-18-2006, 06:24 AM: Message edited by: Ron Eggers ]
Since frames are made of wood that does not have
knot holes, the rabbet surfaces comprise side grain, not a major source of emissions. Only metal
and glass are truly effective vapor barriers and
heat sealing foil/plastic laminates or metal pressure-sensitive tapes can form great barriers.
Plastic paints will not be as effective, but are
probably fine, given the low emission rate that
side grain wood is likely to produce. Gesso, with
its mineral content, is likely to work better than
some other plastic paints.

I thought I read an advise not in DECORE mag. about a year ago that said 3 coats of polyurathane was good as a barrier. Is this wrong????
Ray, see the above "thread killer post" by Hugh.

This means that this thread can now be transfered over to Warped because all pro and con suppasition postings are null and moot.

So Ray, which is it "not in" or "in" "DECORE" or "DECOR"? :D

"Mineral content" Hugh? Talc? It's not just for babies bottoms anymore? Oh and if it ONLY blocked THAT "Off-Gassing".... :eek:
Another conservator I spoke with concurs with Hugh. if we would need a second opinion.


Dave Makielski
Hugh isn't GESSO a mixture of Calcium Carbonate ( Chalk)and some form of Rabbit -hyde Glue?
And as such isn't extremly likely to be Pourious and brittle? But the presence of the clacium carbonate ( used to buffer mats) may lead to the misconception that it is a good BARRIER for the negative properties found in RAW WOOD?
BUDDY wasn't made totally clear, but I believe we are referring here to acrylic gesso, not oil gesso which is indeed made with rabbit skin glue...

...darn, that rabbit keeps jumping back in here, doesn't he? why did Baer ever have to bring that up...

Dave Makielski
Before we had glass and metal, water-borne polyurethane varnish was recommended as a barrier for frame rabbets. The varnish is still OK, but the coating may be inconsistently applied, and it would eventually degrade.

4-ply matboard has been called a barrier, too, but it is really more of a filter. It would work to some degree for some time.

Nothing is as good as glass or metal, our only practical gas-impermeable barrier materials.
Dave I was of the impression that what was being asked was about the rabbet of molding and I also was of the impression the Acrylic Gesso ( Chalk and a Polymer) was more commonly used as a primer for canvases and such ( due to it;s flexibility which in the case of wood wouldn't be a real factor).

But the base is till calcium carbonate and something else which could explain why there may be a misconception that it can serve as a Buffer/barrier to the harms of wood ( which is what is the culprit in mats)

Also I was mistakenly of the impression that the spelling of the two words were different :RABBET and RABBIT.

But then everyone knows how abominable my spelling is.

RABBET is the thing that holds the glass in the frame.

RABBIT is the furry creature that eats carrots and outwits Elmer Fudd in every episode.

(Pesky wabbit!!)

If you watch alot of Looney Toons the doubya probably threw you off, eh??

Tom you mean I had it right all the while? But now we'll have to remember to seperate the third spelling ( WABBIT) lass anyone be mislead bt it's use.LOL

With all those differnt spellings for the same sounding words ( Homonyms?) maybe I have an excuse?LOL

But more importantly which GESSO are we discussing and what are the differances?I wouldn't want to be the cause of anyone being mislead.
Ray, 3 coats of water-based poly does make a good barrier but you're supposed to let it off-gas for a few days before finishing your project.

I use Lineco Aluminum for everyday rabbet lining but I love Marvelseal for larger surfaces... iron-on baby...
Buddy, to make it even more confusing, the word "rabbet" was derived from the word (french?)"rebate", meaning "to recess", or set back. At least that's how Monsieur Paul Frederick explained it to us.
Val even though I live in the N.O. area and the Cajuns think they speak French ,and a lot of colloquialism are truly French derivations I don't have but 1 year ( 8th grade) of training. So I wouldn't know what the French origin was. But if Paul said it you can bank on it for two reasons ,he has been writing instructional books longer than anyone I know of and he was Born and raised in France and i think it is where he began his Framing carrier.

But in all seriousness I did know the correct spelling this time ( even if I and anyone else slipped, at least I don't write like Elmer Fudd speaks. LOL) .I also believe I may be right about which GESSO is meant for coating wood more commonly. Of course to each their own.
Thanks for the Zoology lesson, Bear. This is why bad spellers have more fun.

I appreciate everyone’s input; it has helped to put my friend's beliefs in a new perspective. (And no Baer, it’s not a dark one: I'm not in the habbit.
I have been recently told that canvas stretcher bars should be coated with acyrilic Gesso or Linco sealing tape to prevent the acid in the wood from destoying the canvas. Any thoughts?
Keeping wood gases away from canvas can't hurt.
Heat sealing matal/plastic laminate films from
Marvelseal or Mitsubishi are perfect for this role, since they are complete barriers and have
no sticky adhesive. If they are not available,
plastic varnishes or gessos will help, but adding
a polyflute backing board to keep out pollution
and puncturing accidents may do more good, for the
canvas as a whole.