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Observations on ammonia fuming

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Forum topic by RipFence posted 09-17-2017 08:39 PM 507 views 0 times favorited 5 replies Add to Favorites Watch
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RipFence

67 posts in 2532 days


09-17-2017 08:39 PM

Topic tags/keywords: oak finishing arts and crafts tip

Hello All:
I am currently ammonia fuming all the (QS white oak) parts for a pair of Morris chairs and thought I would share a few observations.
First, I had read from a variety of sources that fuming required ~28% ammonia. That strength is available for about $30/gallon plus hazardous shipping fee of about $20. Pretty pricey. Being frugal (cheap) I decided to try the 10% “industrial strength” ammonia sold at ACE for $5/gallon. It is working great! Parts are darkened to my liking in as little as a few hours or as long as a couple of days depending on the content of the wood and the temperature.
Second, in reading up on fuming I generally saw folks using some sort of custom built tent and fuming the finished project. I’ve done that in the past but in this project I’ve been using plastic storage bins with great results. I put on a few clamps or place a bit of plywood on the top to help the seal. If I sniff around the top I can only detect the faintest scent of ammonia so I’m confident I’m getting a good seal. Using these containers allows me to place them in the sun to heat things up and speed up the process. One of my boxes is clear and I can see the vapor condensing on the inside when its sunny.
Third, if you fume the finished piece the color will likely vary from board to board based on tannin content. By fuming individual parts I can let parts go longer or shorter till I get the color I want. Of course I still get some variation but less than if I fumed them all for the same time.
Of course I wear a respirator with ammonia cartridges, swim googles, and chemical protective gloves whenever I open the box or the ammonia containers but that’s common practice. Anyway, lots of what I read on this topic seemed to make the process fairly complicated. My experience fuming individual parts in storage bins is that its really simple.
EDIT to add two observations and have them all in one place. 1) Yes, googles are needed for the 10% janitorial strength from Ace. 2) The solution looses its strength over time. I guess the ammonia part of the solution evaporates more readily than the water leaving the solution weaker. Keep this in mind because sometimes your piece won’t darken but if you use fresh ammonia it will darken up readily.
Best wishes,
Jim


5 replies so far

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StumpyNubs

7483 posts in 2640 days


#1 posted 09-18-2017 12:30 AM

Thank you for the great suggestions!

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splintergroup

1705 posts in 1062 days


#2 posted 09-18-2017 03:04 PM

I love fuming!

I also swear by the 10% Ace brand, cheap enough and does the job. Typically I’ll use a tent made from a PVC pipe frame and some painters drop cloth. Clear plastic lets me monitor the progress.

For small parts (like boxes), I use a simple 5-gallon bucket. I have a plastic screen that sits up about an inch from the bottom. Pour in the ammonia, add the screen, add the wood, cap and wait. usually I’ll do these until the fuming is as dark as the wood will allow (overnight).

I like your storage bin idea, I’ve been needing an “in-between” enclosure and the bin idea eliminates the setup time involved with a tent. Just need to think up a useful shelf arrangement.

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RipFence

67 posts in 2532 days


#3 posted 09-18-2017 03:59 PM

The bucket is a great idea! Where did you find the screen? I have a tall trash can that could handle longer parts. Just put a plywood top on it and clamp it down.
Thanks,
Jim

For small parts (like boxes), I use a simple 5-gallon bucket. I have a plastic screen that sits up about an inch from the bottom. Pour in the ammonia, add the screen, add the wood, cap and wait. usually I ll do these until the fuming is as dark as the wood will allow (overnight).

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splintergroup

1705 posts in 1062 days


#4 posted 09-18-2017 07:56 PM

Jim, the screen was from an old refrigerator. Plenty of plastic contraptions (colanders, etc) in the kitchen cabinets that work to keep the wood out of the ammonia pool (just don’t tell the wife 8^)

For the bucket, I don’t use the snap-on lid since I want to avoid any sloshing/splashing so I use a piece of plywood with some thin foam from packing material as a gasket. The top is weighted closed with a rock….

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RipFence

67 posts in 2532 days


#5 posted 09-25-2017 03:16 PM

One new observation: I wondered if goggles and respirator were really necessary with the 10%. Well, yesterday I forgot to pull my goggles down before I opened the lid. I felt an immediate irritation in my eyes. It was mild but enough to get my attention. So the answer is yes, goggles with 10%.

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