Make your own "Seed Dryer"

[ContainerTed]

Every year, I am always wondering what to do with all the paper plates of drying seeds. I usually run out of places to set them. I decided that I could make a "box" of sorts that could hold several of the paper plates (in this case up to 20) and circulate some air around them to help speed or enhance the drying process. So, a few days ago, I rolled out the table saw and started cutting up some plywood and raw sawmill poplar. The pictures show the results.

This is my prototype for a seed dryer for the backyard gardener. Now, let me emphasize that this is a rough prototype meant only to prove the concept. I normally use the super-cheap paper plates to dry seeds. The dimensions for this project were driven by the diameter of those cheap plates. Now that I've got a basic design that I know works, I'll make one that is much more pleasing to the eye. You know, without all those rough edges you see in the attached pictures. This one was done to prove the design, and was thrown together with lots of "scraps" from my woodworking waste barrel. The design works so well, that I just had to go ahead and show it here so that others might make a similar box for themselves. It was done with scraps and lots of used parts cannibalized from all kinds of things.

The basic box is constructed from AC grade 1/2 inch plywood. The door was made from some scrap poplar and a piece of plexiglass rescued from the scrap barrel at Lowes. The air is circulated by a 12 VDC "mufffin" fan salvaged from a dead computer. The 12 volt power adapter cost me $1.00 at a local thrift shop.

The individual shelves are spaced 1 inch apart (on center) and there's a total of 20 shelves in this design. Except for the very top one, the shelves do not go all the way to the back of the box. This is to allow maximum air circulation. The top shelf, however, does contact the back plate. This allows the top shelf to be a "quick dryer" of sorts because all the air circulating within the entire box must pass over this shelf to exit at the top rear.

It was simple and quick to make. I used one of my table saws to cut the dado's for the shelves, but a router or even any circular saw could also be used. The shelves shown are mostly masonite, but there are a few made of 1/8" plywood paneling pieces.

The muffin fan is very quiet and the air moves gently but steadily. I used a piece of an old hepa filter to cover the bottom air intake area, and a piece of ordinary window screen on the top rear air exit holes. The door clasp is made from one of those elastic ponytail thingies that most women have a few of, and a wood screw plus a few staples to hold it in place.

This device really works and cuts my average total drying time by at least one-third - probably more.

Enjoy and let me know if you have any questions.

[Zana]

I like your concept, Ted. Will have to ponder on it until the next year when I'll get to save seeds.

Thanks for the ideas here.

[Douglas_OW]

Ted,

Looks good. I can't quite visualize how the air flows over/around each shelf. It seems like you could get better flow if you alternated the shelves- first pushed all the way to the back, next one pulled forward touching the door, etc.
Did you consider putting a lip on each shelf, just in case one of the plates get jostled? Maybe a bead of bathroom caulk, like a little dike? I'd hate to dump seeds from the top tray onto the 19 below it.
If nothing else, your cabinet should protect the drying seeds from stray winds and kids and kittens, et. al.

Jim

[ContainerTed]

Jim, I considered alternating, but it didn't seem to be worth it. That would put the collective humidity of all shelves flowing over everything in the case as you progress upwards. The amount of airflow is adequate to exchange the air on each of the shelves quite quickly. I have really intended to use the top shelf as a place to begin fresh fully wet seeds and slowly move them down a few levels at a time.

The paper plates sit very solidly and are not easily bumped around. I don't have the kid nor the kitten problem, so I ruled those out of design influence as well. And, there just isn't enough room to "dump" a tray from anywhere in the column. As long as you use a minimum of care when putting new paper plates in, there shouldn't be any problems. In a month of use, I never had a single loose seed anywhere.

What I think is the primary advantage is that the paper plates don't have to be stacked touching each other, and the whole operation takes up a much smaller footprint.

As far as "stray winds", I keep this dryer indoors. It has its own permanent location on a low shelf in the extra bedroom.

[Douglas_OW]

Ted,

Those were just some thoughts I had. Its hard to know how you are using the cabinet, or how many fresh plates you might be loading at any time. If you intend to add and remove plates at some irregular schedule, I would think that the newest, wettest, plates should be put in the location FURTHEST from the air intake, otherwise you will be blowing more humid air over the plates that have been drying longer.
Anyway, I like your idea and I'm sure that it will work for you the way you want it to.

Jim

[JamesL]

Nice concept and build Ted.
Like the compact footprint.
Please post the plans when you are ready to share them.

[Salsacharley]

Outstanding!

[FaithHopeLove]

I love this idea and it reminds me of an incubator for chicks.

[habitat_gardener]

Great idea! I immediately thought of drying herbs in something like this. I usually air-dry my herbs, but this would be an efficient way to dry small quantities of many different herbs.

To increase airflow, you could make the shelves out of window-screen material, though you'd have to add some supports so that the screening did not sag. Maybe that stiff plastic mesh sold in crafts stores ("plastic canvas") would work. On the other hand, you wouldn't want seeds falling through the holes in the mesh...

[newatthiskat]

I was thinking the same thing. Looks like a home made dehydrator. You might make shelves that fit into the groove made out of screen product that is somehow stabilized. Use it as a dehydrator in the off season of seed drying. Presto chango you have dual purpose.

[ContainerTed]

The prototype draws air in at the bottom and exhausts it out at the top. I'll do a workup with some dimensional photos when I build the "not so rough" one this winter. The spacing of the shelves shown above is one inch on centers. But it could easily be anything you feel works for you.

Herb Dryer? Dehydrator? Yes, those are easily other uses. But, that might suggest some kind of heat source. I had originally thought of using some Christmas lights in the bottom to create a gentle flow of air up the column. The amount of heat could be somewhat controlled by the size and number of bulbs turned on at any given time. Another heat source considered was a heating pad, which would have at least three different settings.

There are some sheets of plastic mesh designed to help dehydrators deal with smaller objects being dried. The ones I saw at a store were not rigid and would require additional support structure to each shelf. Window screen could be used, but after trying a couple of "screen plus support" ideas, I found that the only way to make that work was to make individual slide-in shelves that were basically a frame for the screen. That might add some height to the project to get the same number of shelves. Or, you would have to reduce the number of shelves. It would certainly add some weight.

The outside dimensions of the cabinet are driven by the paper plate. In the case above, the plate is ~9 inches. I added two inches to that to give plenty of room to the "plate in and out" process. So, it's 11" x 11". I have 20 shelves one inch apart, plus the cavity for the muffin fan. That made the height ~23 inches. So, 11" x 11" x 23" is the final envelope. The key here to let whatever you put the seeds onto to dry be what drives the width and depth. The height is driven be how many shelves you want.

Again, this was built out of scraps from the waste bin. Mostly, the rough appearance is due to making things "functional". Pretty can be done in the "production" model.

Also, my brother, who is a smoker, blew a lot of cigarette smoke into the cabinet for me. It was pretty thick thruout the inside. The little fan cleared all traces (except for the stink) in less than 10 seconds. That means the total air exchange is just about where I hoped it would be - good overall exchange with no "seed-moving breezes".

[amideutch]

Looking good CT. One thing you might try is to reverse the airflow. Most exhaust fans set up in greenhouses for humidity control are located near floor level as that is where it accumulates. The dryer air being higher up. Also with the air intake at floor level it will be subject to pulling in more dirt as we learned at work where the PC's located on the floors were totally filthy on the inside when we opened them up to clean versus the PC's located on the desk tops which were a lot cleaner.

Ami

[ContainerTed]

Originally Posted by amideutch

Looking good CT. One thing you might try is to reverse the airflow. Most exhaust fans set up in greenhouses for humidity control are located near floor level as that is where it accumulates. The dryer air being higher up. Also with the air intake at floor level it will be subject to pulling in more dirt as we learned at work where the PC's located on the floors were totally filthy on the inside when we opened them up to clean versus the PC's located on the desk tops which were a lot cleaner.

Ami

Ami, everyone knows that government computers are built to a MIL-SPEC and have their own self cleaning functions.

Your points about the humidity and air flow at floor level are well taken. But, I do have an assigned location for this device. I'm getting too old to be bending down to floor level all the time. So, I will have this on top of a chest of drawers I use for storage of hobby stuff. This will have it at the "no bend over" height and out of the dust.

I'm also going to put in the lights I mentioned above and make the production model a dual function product - a little bit of heat for herbs and such and a little bit of gently forced air for tomato and pepper seeds. I have a couple of other ideas that I may incorporate into the final design, but that will be decided during some additional trial and error efforts. In the end, I may be able to refer to it as "multifunctional".

Technology must advance --->

[Douglas_OW]

Ted,

You might be interested in some similar cabinet designs that others have made. Try Googling "solar dehydrator" or "solar dehydrator plans". The cabinet section of these is very much like your's, but in a larger scale. You might get some insight from their design decisions and modifications. I realize that for seed drying, you don't want the high heat that the solar collector provides, but the cabinet section has the same design requirements.

Jim

[johnashearer]

Very Nice. Thank You.

I will be building this soon.