Ammonia Fuming/Tempered Hardboard?

QSWO primary material, 12" square, 1/4" tempered hardboard secondary material, and that must be pre-assembled before finishing.

Fuming with ammonia is the desired/preferred method of finishing.

Question: Would the ammonia fuming process have a detrimental/any effect on the tempered hardboard?

Lots of conjecture already, thanks ... need some BTDT, if possible.

TIA

Reply to
Swingman
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Wellllll since no one has answered yet and I have absolutely no Idea, Spearmint on scraps. ;~) IIRC Amononia displaces moisture and if it does not hurt the wood it should not harm the hardboard IMHO.

Reply to
Leon

I do know that some tempered hardboard is made with a tannin based adhesive to reduce formaldehyde emission, and guess what ammonia reacts with ...

Based on what little of my organic chemistry I remember, I suspect that any reaction with the ammonia may just make the hardboard harder/brittle, but I don't have time to do the testing and was hoping for a chemist in residence, or "...a yeah I tried that, don't do it".

Damn ... I just hate to do $omething for someone that is going to bite me in the butt two years down the road.

Reply to
Swingman

What about a sealer coat of shellac on the hardboard before assembly. Or does ammonia penetrate shellac? Joe

Reply to
Joe Gorman

Reply to
nospambob

Ammonia will ruin shellac (you can use it as a stripper for old shellac). However it does nothing special to hardboard and even tannates will only be darkened by it.

Reply to
Andy Dingley

Thank you, Andy ... I would have been willing to bet Greg G.'s next weeks beer ration that you would have known the answer. ;)

Reply to
Swingman

Thanks, Now that I had my learning experience for the day I can spend the rest of it in a daze.

Reply to
Edwin Pawlowski

So don't sniff the ammonia !

Reply to
Andy Dingley

More conjecture I fear, but based on a bit of experience.

Tempered hardboard seems to have an affinity for absorbing moisture if it's not sealed. Learned this via my TS cast iron top which I cover when not in use with a piece of HB. Surface rust within days even through TopCote. Sealed the HB with a wash coat of shellac and the problem went away.

Ammonia fumes (NH3) and water (moisture) combine to form ammonium hydroxide (NH4OH) which is, depending on concentration, a pretty powerful base. If it won't eat cellulose fiber it's the only strong base I've ever heard of that won't. I used a nail board made from HB to support some cherry I fumed and it was real spongy after 48 hours in the fumes - I suspect moisture in the HB, and then good old ammonium hydroxide had its way with the fiber.

Suggest you seal the HB with a coat of varnish, poly, anything but shellac before fuming.

Reply to
Tom Banes

Doesn't sound a bit like "conjecture" to me ... if that's the case, it's back to square one.

Thanks for the input.

Reply to
Swingman

Perhaps an email fired off to the Masonite Corp.

Reply to
Leon

I did, and not only did they reply back, they also called this afternoon ... this despite the fact that they no longer make any sheetgoods whatsoever.

Very nice fellow (Director of Communications) said they turned it over to their wood science department, got back a "ton of information" and:

"Bottom line- the Ammonia shouldn't cause a structural problem. The board surface might get a little fuzzy, but it should still be ok."

I told him I would no longer hesitate to put Masonite doors in some of our houses. ;)

Reply to
Swingman

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