The effect of temperature on fuming

[Jim Morvay]

I have just completed a QS white oak coffee table that I want to fume, but am now concerned how temperature might affect the process. Do any of you who may have fumed oak have comments, one way or the other, how temperature comes into play? I fear I may be too late for this time of the year, given that we had our first snowfall this past weekend.

[John TenEyck]

You'll get more consistent results with dyes and they aren't dangerous to use like concentrated ammonia is. Maybe the cold weather is a sign.

John

[Carl Beckett]

I just fumed a chair a couple weeks ago. Daytime temps in my shop were low 60's. It went slower than the test sample I did back in July (was overnight). What seemed to help was switching to a sheet type pan for the ammonia where there was a lot more surface area for evaporation.

Lower temp did seem to slow the process, but I wasnt in a hurry so it sat the entire week and came out just as dark as my test samples.

I was using household ammonia from Walmart so not very concentrated (I figure it somewhat saturates in the enclosure anyway - based on temperature, so not sure there is a benefit from higher concentration other than speed)

Just my experience.

[Dave Cav]

I fumed several pieces at my former shop in western Washington; temps in the high 60s and lower at night. I used the high strength ammonia from a blueprint place and didn't have any problems. The high strength stuff is nasty; you need a respirator, gloves and eye pro any time you're handling it. You don't want to use aluminum containers for your ammonia. Glass or steel (or plastic).

[Jim Morvay]

I'm well aware of the non fuming methods, but would prefer to try fuming.

[Jim Morvay]

Was your shop standalone or part of your home? If the former, probably no real concern, but our home has a walkout lower level of which my shop takes up a third and is under the master bedroom suite. At the other end is the garage which is also heated and I'd have no concern about getting it down into the high 60's, but I'm afraid the ammonia fumes would still make it upstairs given that I'm using the 30% stuff.

[Jim Morvay]

Using 30% and have everything I need to handle it, but just read that higher temps tend toward red while lower temps tend toward gray. And now that we haven't seen anything above 40º in the last two weeks, I suspect I've missed my window for now and will have to set this aside until Spring.

[John TenEyck]

Stick a light bulb in your fuming chamber if you want higher temps. Put it on a thermostat, like I used to do to keep the outside cat house warm in winter. You can buy 110v thermostats at McMaster Carr, etc.

John

[roger wiegand]

As a general rule of thumb, the rate of most chemical reactions doubles with each 10 deg C increase in temperature, so you can expect the fuming process to take four times longer at 10 (50 F) than at 30 (86 F). I don't know what the basis for different colors might be, there's not enough of a difference in those temperature to cause a different reaction to happen, I would think.

[Jared Sankovich]

I fumed a couple file cabinet panels about a month or so ago when it was running about 80 in my shop. They came out gray not red. I actually had to use a red dye to warm up the tone to match the original file cabinet.

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