Making a shrink pot may be the most magical thing you can do in green woodworking. You can carve bowls and spoons from dry wood, but a shrink pot’s gotta shrink. I revisit the process regularly, and I was working on the one above from a bent length of quaking aspen (Populus tremuloides) from a recent windfall. So I thought I’d share some photos from my work with this one detailing a few steps to encourage you to share in the fun.
I’ve written a bunch of posts about shrink pots, beginning with this one that presents the general idea.
I’ve discussed my process for boring the initial hole and the rest before (see the other posts), but for this one with a bit of curve along the 10″ length, I went half way in from both ends at a bit of an angle to each other — aiming for the center in the middle. Then I widened and shaped the curving interior by working along the grain with a gouge from both ends.
After the inside is formed, I shave away the excess material from the outside, but just to a rough stage. Much more will be done after drying. Depending on the size and design of the pot, I leave a wall thickness of 5/16″ to 1/2″ at the base. 3/8″ (9mm) is a good general target.
Next comes the groove for the bottom, but it’s worth taking the time now to make sure the bottom is flat and that it supports the pot above vertically or however you’d like it to sit. One way to at least make sure there’s no wobble is to rub a pencil on a piece of paper, then rub the pot bottom over that.
The graphite will transfer to the high areas.
You can shave them with a knife, but I like to use a block plane while pushing the pot down against the upper edges of my partially-open vise jaws. Any gap between boards will work.
Here’s the cutter I used to form the groove in this pot. I wrote about making it here.
I cut a slight outward taper from the groove to the bottom of the pot with a knife (forgot to take a photo — the shot above is before that). You can cut a (slightly different) groove with a knife, and there are other ways as well.
I trace that inner rim to a dry board, but in this case, it was still a real circle, so I just measured and struck the board with a compass.
I cut it out roughly with a coping saw, then trim to the line with a knife, followed by chamfering both upper and lower corners to form a V profile to the edge.
It should be a snug fit on the way in, requiring some pushing and/or tapping.
Then, with a little “pop,” it will find the groove. It will shake around in the groove at first, then become tight over the next few days as the walls constrict around it.
Once it’s dry, you can go ahead and make the finished pot, or you can wait quite a while. But I’ve waited long enough! I’m ready to get back to these now, with lots of ideas.
Thanks for the encouragement! Great pics and narrative on the process. I am really curious about your square shrink pot — I doubt it will shrink as evenly as a round one, but how will it shrink? Will it need to be re-shaved to sit squarely (no pun intended) on the table? It then opens up the world of possibilities for other shapes as well.
Amazingly, it shrinks about the same as a round one. I keep the inner corners rounded a bit. To a certain extent, the walls conform to the shape of the bottom as they shrink. This post features a good shot of a square shrink pot where you can see the bottom well: https://davidffisher.com/2016/11/10/bent-warped-and-twisted/
Here’s another square one, with no twist: https://davidffisher.com/2018/10/07/shrink-pots-paint-and-lettering/
And you can do rectangles as well. About halfway down this post, you can see one that mimics a book in form with a rectangular base: https://davidffisher.com/2017/11/13/learning-from-lettering/
Ovals work fine too: https://davidffisher.com/2017/03/19/fish-say-shrink-pot/
And shapes that follow the wonkiness of a natural form: https://davidffisher.com/2019/03/28/a-couple-shrink-pots-and-spoons/
So many fun possibilities.
Usually, there’s no change in the flatness of the base after drying, but little touch ups with the block plane are easy if needed.
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Great post, thank you for sharing this… Can’t wait to see them finished! I have been playing with some pots this winter and I was curious, what species of woods would you consider “best” for the pots?
Just about anything will work, but I’d shy away from ring-porous hardwoods like oak and ash. There might be more of a risk of splitting along the ray plane as the walls tighten around the bottom. If I were to make one of ash or oak, I would make the bottom a little on the looser side to begin with.
I’ve made them out of all sorts of things: apple, maple, birch, aspen, cherry….
About the only thing I’ve had a problem with was American Sycamore. It tends to move quite a bit as it dries, and I experienced some cracking in most of my attempts with it.
Of course, you’ll have a bit of an easier time with woods on the softer end of the spectrum like some of the birches and aspen in terms of removing material, as opposed to hard maple or apple.
I have some pots in the process right now, great fun and relaxing, compared to the tediousness of some casework. Will soon go out and find some Yellow and White birch to work on the next few months. Thanks David, really enjoy your blog.
Yep, John, the pots do feel more like play. Thanks for your comment.
Really enjoy all your posts! Thanks for so much inspiration over the last few years. I’ve made 4 strink pots form Striped Maple. Left the bark on some, just because it is so beautiful.
I love that, Steve. Shrink pots are a great way to preserve the beautiful bark in a section of tree. I’ll bet striped maple made really striking pots.
Great article, many thanks David!
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I read all your articles about bowl carving and the basic tool recommendations as well. With regards to shrink pots: if you could choose just one gouge which one would it be? I don’t have a straight one yet and don’t want to buy a bunch of them..
Thanks in advance!
Hi, Max. First of all, you don’t necessarily need a gouge to make shrink pots. Especially for smaller pots, say 3″ diameter and 4″ high, it is quite reasonable and enjoyable to remove material from the interior (after boring) with a sloyd knife or a hook knife. This involves rotating the pot as the knife is held withing and pulls up lovely cross-grain shavings. I still do some pots that way and it leaves it’s own unique texture. But for taller pots especially, the gouge can reach in a bit better and can hog away material quickly from wide pots. I would suggest a #8 or #9 sweep, 20-25 mm wide. The sweep is more important for removing bulk, as you don’t want the corners digging in and burying themselves. Such a gouge, especially the #8 would be useful in many other ways with your woodworking and carving as well.
I started my first Shrink Port today. I don’t have a T-Auger, but tried a standard auger bit in a brace. I couldn’t get the snail to hold in the end grain. I tried one bit with a fast lead and one with slow lead with equally pore results. I ended up using a 5/8 spade bit which left a lot of material to split out with gouges. I used both standard and in-cannel gouges for this. It was pretty slow going until I got about a 1″ hole then things freed up pretty well.
To cut the bottom grove I used a cutting gauge to start it followed by a narrow #3 gouge to bevel up from the bottom. I used a back bent #5 gouge from the top to cut the upper bevel. It took about three passes to get an acceptable grove. My tip to others is to use the point of a spoon carving hook knife to deepen the apex of the groove as you go. it reaches right in from the bottom and makes this task easy. As this is my first attempt I am a little apprehensive about the bottom fit. Time will tell.
Do you do anything to “clean-up” the interior after drying ?
Those are great ideas, and a perfect example of understanding the concept and using what you have to get there. When cutting into end grain, the lead screw on the auger is important. It needs to be relatively aggressive with some depth to the threads. Also, touching up the cutting lips of the auger makes a big difference. I use my old 2″ T-handle auger for most pots, but for some smaller pots and shrink tubes I’ve made, I’ll use a brace and smaller auger bit. I have a couple sizes of these auger bits from Lee Valley https://www.leevalley.com/en-ca/shop/tools/power-tool-accessories/drill-bits/45003-single-flute-auger-bits and they work very well for end grain boring in green wood. The lead screw holds very well, considering the difficulty of the task. I find that the hex shank holds fine in my brace chuck, but you can also use them with a power drill if you have one with enough torque.
Sometimes I’ll tidy up the interior with either gouge or knife. Depends on the situation. Sometimes just the upper portion.