De-humidor? is that a thing?

Please put your pickup/wiring discussions in the Electronics section; and put discussions about repair issues, including fixing errors in new instruments, in the Repairs section.
Post Reply
User avatar
Ryan Mazzocco
Posts: 605
Joined: Sat Feb 04, 2012 6:01 pm
Location: Joplin, MO
Contact:

De-humidor? is that a thing?

Post by Ryan Mazzocco »

I've researched this question before posting, but am unclear on a few things.

I have some instruments that I would really like to work on but the humidity has been crazy high in our shop, like 80% and higher. We cannot keep it out of our shop. It's not a very humidity-tight building anyway and it's always a struggle but right now our AC is out and the dehumidifier alone can't keep up.
I have top/back plates ready to brace and the braces are ready but I don't want to to glue them up in this condition. I put it all in a chip case and brought it inside my house hoping it would do better, but this isn't working. Even with the central AC running constantly the humidity in the house is staying above 70%+ most of the time.
I have about 8' of open space under my work bench. I was thinking of enclosing that space to keep dehumidified and store materials in until I need to use them.
I'm sure I can keep a small, 8x2x4' space regulated pretty consistently, but the question becomes, what happens when I bring the material out to work with? Let's say I keep the plates and brace material at equilibrium in 40-45% RH and then bring it out to glue up bracing? Can I glue up and then put back in the dry space before it takes on too much moisture? At what point can I bring the parts out into the higher humidity environment? once braces are on? once the the box is closed? I realize ideally that it should be kept constant through the entire build process. But at the same time, it will leave my shop at some point and if it stays in this area of the country it's going to be between 60-80% RH environment it's whole life.
Thoughts? Thanks
Aaron Helt
Posts: 79
Joined: Thu May 10, 2012 9:19 am

Re: De-humidor? is that a thing?

Post by Aaron Helt »

My setup is a set of lower kitchen style cabinets with a humidistat controlling a light bulb. I set the humidistat at 45%. Obviously this is where I keep my wood and partially build guitars in. My garage is not controlled. I only take the wood out for bracing when the garage is close to 45%. I’ve built 22 over 20 years and none have had problems with cracking or swelling. This isn’t ideal but it is the best I can do. The top of the cabinets is my primary work surface.
User avatar
Barry Daniels
Posts: 3186
Joined: Thu Jan 05, 2012 10:58 am
Location: The Woodlands, Texas

Re: De-humidor? is that a thing?

Post by Barry Daniels »

I think there have been some lengthly discussions here about this. You might try searching the library for "drying cabinet".
MIMF Staff
User avatar
Ryan Mazzocco
Posts: 605
Joined: Sat Feb 04, 2012 6:01 pm
Location: Joplin, MO
Contact:

Re: De-humidor? is that a thing?

Post by Ryan Mazzocco »

Barry thanks for the term to search. I kept trying to search for humidor and was coming up with very few results and not very helpful.
Clay Schaeffer
Posts: 1674
Joined: Fri Jan 06, 2012 12:04 pm

Re: De-humidor? is that a thing?

Post by Clay Schaeffer »

Humidors are used to keep cigars moist, rather than drying things out.
I use a plastic lined closet with a small portable dehumidifier when I need a humidity controlled space. I remove the work only during the time it takes me to apply the glue and place the clamps and then return it to the humidity controlled space. After the body is complete I will remove it from the humidity controlled closet, but I will return it to the closet and let it acclimate to the lower humidity before I attach the neck.
Randy Roberts
Posts: 465
Joined: Sat Jan 07, 2012 9:11 pm
Location: Omaha, NE (a suburb of Iowa)

Re: De-humidor? is that a thing?

Post by Randy Roberts »

Ryan,
My "completely climate controlled" shop (read - completely controlled by the climate) is also just my garage.

What has worked well for me was discovering that you can get really large ziplock plastic bags at some home interior type stores. They usually are sold to store clothes in, and are pretty air tight especially compared to plastic storage boxes.

What I do is store my pieces (braces, joined tops and backs etc.) in the bags, and throw a few small packets of dessicant gel in the bags with the wood. I can then just hang the bag of wood from a nail on the wall. Keeps it all dry, out of the way, and safe from me and my ten thumbs until the weather gives me good glue up conditions. It also keeps all the parts for a given guitar together and prevents losing pieces, as I tend to have large gaps of no time to build.

I get the dessicant packets free, as they come sealed in lab test kits at work, but you can buy silica gel dessicant on the web easily enough. The dessicant packs can easily be recharged by drying them out in the oven when the wife's not home.

I am still pretty picky about humidity during the glue-ups, and double check 4 cheap humidity monitors against my psychrometer just before working with the wood. You could also use Mario's ingenious ice water in a pop can method [search the library here to find the long thread on it's development] if you don't have a psychrometer (wet bulb/dry bulb thermometers).

I don't see a problem caused by storing it at what is probably less than 40% in these bags, as long as the glue up is at the humidity I want, as I believe wood this thin equilibrates pretty quickly to it's environment. I do bake my tops in the oven (definitely only when the wife's not home!) to drive out all free water and then let them return to 40% equilibrium before joining. Tops and backs aren't going to be at risk of ripping themselves apart from being too dry while stored as free plates. The danger is once they are locked into the box at their circumference.
Randy Roberts
Posts: 465
Joined: Sat Jan 07, 2012 9:11 pm
Location: Omaha, NE (a suburb of Iowa)

Re: De-humidor? is that a thing?

Post by Randy Roberts »

I timed out doing searches...
Here are a few worth reading maybe, but I can't find the long thread on using a glass of ice water or a pop can filled with ice water that uses the point that condensation appears on the surface of the can as when to read the second ( wet bulb ) reading. Anyone remember that thread?

http://www.mimf.com/library/Mario_Proul ... -2007.html

http://www.mimf.com/library/Humidity_is ... -2010.html

http://www.mimf.com/library/Bad_back_cr ... -2009.html
Alan Carruth
Posts: 1265
Joined: Sun Jan 15, 2012 1:11 pm

Re: De-humidor? is that a thing?

Post by Alan Carruth »

Somewhat better than a dry box is a tent around your main workbench. You can frame something up with strapping and 2xs, and cover it with plastic. Hang an old storm door on it and dry it out with a dehumidifier.
User avatar
Barry Daniels
Posts: 3186
Joined: Thu Jan 05, 2012 10:58 am
Location: The Woodlands, Texas

Re: De-humidor? is that a thing?

Post by Barry Daniels »

Ervin Somogyi's shop is a drafty old house in Oakland, CA and he built a sealed, humidity-controlled room inside one of the basement rooms. It looked like he used materials normally used to build enclosed patio rooms. It even had a spring loaded storm door over the entry.
MIMF Staff
Simon Magennis
Posts: 471
Joined: Sat Jan 07, 2012 7:51 am
Location: Menorca. Spain.

Re: De-humidor? is that a thing?

Post by Simon Magennis »

This is what your are looking for.

http://www.mimf.com/phpbb/viewtopic.php ... 01&p=15568

The tin can thread is one of my all time favourites. Thanks Mario.
Randy Roberts
Posts: 465
Joined: Sat Jan 07, 2012 9:11 pm
Location: Omaha, NE (a suburb of Iowa)

Re: De-humidor? is that a thing?

Post by Randy Roberts »

Simon,
BINGO! - That's the summary of what got worked out and should be in everyone's shop skills.

The thread that led up to that one, that had the endless discussions of why and why not, etc., would have been a great trip down memory lane though....
Simon Magennis
Posts: 471
Joined: Sat Jan 07, 2012 7:51 am
Location: Menorca. Spain.

Re: De-humidor? is that a thing?

Post by Simon Magennis »

Randy Roberts wrote: ...
The thread that led up to that one, that had the endless discussions of why and why not, etc., would have been a great trip down memory lane though....

You asked for it, you got it. :-)

http://www.mimf.com/phpbb/viewtopic.php?f=12&t=1672
Randy Roberts
Posts: 465
Joined: Sat Jan 07, 2012 9:11 pm
Location: Omaha, NE (a suburb of Iowa)

Re: De-humidor? is that a thing?

Post by Randy Roberts »

Simon,
Thanks a bunch! how did you find it? I tend to have trouble doing searches that get what I'm looking for.

Anyway, thanks. I felt so much younger for 20 minutes.
Post Reply

Return to “Flat-Top Acoustic Guitars and Bass Guitars”