# Turning a Coffee Mug



## Sprung (May 22, 2018)

Had some requests for a classroom thread on turning a coffee mug. Finally getting around to turning some more mugs, so figured I'd document the process and make a thread. Please note, this is only the way I make these. There's probably other ways to do some of these steps, maybe even better ways. But, this is how I do it.

Here's where we're headed:



 

What you will need:
Mug insert. I use this one as it's the best price I've found. I vastly prefer the screw on lids.
A chunk of wood. 4" x 4" x 8" is what I prefer to start with. I could get away with as small as 3 5/8" x 3 5/8" x 7" if I'm very careful, but I like the little bit extra material to give me some wiggle room to start. I like using both solid wood or laminating pieces together. Some people do stave construction. Others segment rings. I just like the look of the wood in a whole block or laminated blank.

First you'll need to mark the center of each end and then turn the blank round between centers. Make a tenon on the one end to be grabbed with the chuck.



 

Next, chuck it up and drill it out with a 2 1/8" forstner bit. I use this bit. I have drilled out close to 20 mug blanks with it so far and it's only now to the point where I've decided I'll hit it with the diamond card and sharpen it before I use it again. And that's pure end grain drilling.

If you are using the insert I liked to above from Woodcraft, drill to a depth of 5 3/4".



 



 

At this point, if you're using a piece of wood that isn't fully dry, it's time to set it aside until it's dry. How long to dry will depend on species used and your climate and shop space. For me, it takes about 6 to 9 months to dry out a blank in my basement once it's been drilled out and had the end grain sealed. (I usually seal with wood glue thinned with just a touch of water.)

After it's drilled out, I give the outside of the mug a few passes with the tool to get it round, in case it's even a little off from mounting in the chuck. It helps me with my visual perception in the upcoming hollowing step. I also face the front end just drilled into so it's even.

I then measure the exact depth of the hole and make a mark on the outside of the blank where the bottom of the hole is. I make another mark about 5/8" to 3/4" past that to mark where the bottom of the mug will be, so I get a visual when I go to start shaping. You'll notice that I then took these marks and extended them so they go all the way around the blank.



 

The first line helps with keeping track of where the cutter is on my hollowing rig. Can you manhandle a tool and turn one of these without a hollowing rig. Yeah. I've done it, but I certainly don't recommend it. This is just much safer and easier to hollow with a proper hollowing rig.

The one downside is that my lathe is too short for one. But, not a problem. You can see the solution I came up with to mount it. It works well for me.



 

Here's why we marked the first mark. It helps you visualize where the bottom of the mug is so you don't go crashing into it with the cutter. The laser on the rig is quite helpful.



 

Then it's time to hollow. Remove any material from the inside of the blank that keeps you from sliding the insert in all the way. The 2 1/8" bit is the rough diameter of the small end of the insert and the hollowing you do will end up roughly tapered to be wider at the opening than at the bottom. Stop often to check fit. At the top end, I don't want it very tight - I always leave just a little wiggle room to leave some space for the glue that I use to glue in the insert.

After that I hold the insert in and trace around it with a pencil. This gives me a reference point in shaping where, once I reach the pencil line, it's time to be careful with how much material I'm removing and to check the fit of the insert often. You want the lip of the insert to be able to slide down over the wood and have a nice fit all around the outside.



 

Sometimes I get the insert completely fitted at the top before I do any shaping, as in this pic.



 

Before I start shaping, I remove some material from the bottom end. This helps me to visualize where the bottom is in shaping and properly shape it.

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## Sprung (May 22, 2018)

Then I get to shaping. There is room for some variation here, if you'd like. You can see in the first pic above that all three have their own shape. I do always go narrower at the bottom though.

This one isn't completely shaped in the pic, but it's almost there.



 

I prefer to work with blanks that are free of voids, checking, etc. Since this is something that will be used to contain hot liquids, I am mindful of what heat does to things. Epoxy softens at about 140F, so that's definitely out. CA is good to about 180F or so, from what I've read, so it should be fine. I will be testing my first fill and how it stands up. This blank was completely clear on the outside, but revealed this. I filled it in with finely ground coffee and CA. It'll be going to a family member who will be my guinea pig to see how/if the repair holds up.



 

After shaping, I sand with 120grit, lathe on and then lengthwise with the lathe off. Then do that again with 220grit. I haven't gone higher than 220grit on any of the mugs I've made.

After sanding, I start eating away at the excess on the bottom. I stop when it's about 5/8" in diameter and, with the lathe off, use a saw to cut it loose.



 

Then I chuck it up the other direction and remove the stub from the bottom. I also shape the bottom so it's not flat, but a little concave. After that, sand with 120 and 220. I also, with the 220, ease the edge of the bottom just a touch so it finishes better and without a sharp edge.



 

After that, I give it a good cleaning with compressed air. And a wipe down with lacquer thinner prior to finishing.

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## Sprung (May 22, 2018)

Ok, it's taken me far too long to get the final steps ready to post. But, here they are.

After turning and sanding is done, it's time for finishing. Apply the finish of your choice. Wipe on or spray poly or a lacquer will all work just fine. You do want a finish that will seal the wood, an enough coats of it to ensure the wood is sealed, since it's certainly going to end up coming in contact with liquid.



 

After the finish is cured, it's time to glue in the insert. I've used two different adhesives for this. They both work. I prefer the RTV silicone and it has worked for me 100% of the time. The downside is that any squeeze out is harder to clean/remove from the surface of the mug. The E6000 is easier to clean any squeeze out, but I have found that sometimes in the low air environment of the inside of the mug with the insert in, it doesn't always fully cure and then I have to re-glue it. So, I pretty much stick to the RTV silicone.



 

I don't have a picture of it, but fill the lip in the top of the mug insert (with the insert sitting upside down) with adhesive. I also put a few globs about 3/4" up from there to get another contact point inside the mug for the adhesive. From there, slide the wood portion down over the insert and start to push into the top of the mug.

After that, it's time to clamp it. I use parallel clamps for this - always lines up and I only need one clamp per mug. I leave clamped for at least a few days to make sure the adhesive has some extra time to cure. In the inside of the mug, with very tiny amounts of air in it, I have found it takes a little longer to cure. It is important to leave them sit in the orientation pictured so the adhesive doesn't run on the inside of the mug - and if it does, it runs to right where you want it. The RTV silicone doesn't really run, but the E6000 will for certain.



 

After it's removed from the clamp, I clean up any squeeze out from the adhesive. E6000 just rolls off like the silicone it is. The RTV silicone I try to be more careful about not having so much squeeze out. Some of it will pull off, but I usually have to go back with a piece of plastic (so as to not damage the finish on the mug) to scrape off the excess.

From there, enjoy your finished mug! I really enjoy making these.

I do include the following care instructions with them:

Please wash before first use. When washing, do not submerge body of the mug – it is hand wash only with a damp rag. The lid may be submerged, but is not dishwasher safe.​

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## Sprung (May 22, 2018)

.

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## Lou Currier (May 22, 2018)




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## Sprung (May 22, 2018)

I have a few that I sprayed the last coat of finish on this evening. Once I get them assembled and done, I'll update the above post with pics and details.

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## ripjack13 (May 22, 2018)

Matt, I gave you a double post, just in case you needed additional room for pictures.

Nice write up. This is the kind of stuff that I like to see here. Well done. Thank you....

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## Wildthings (May 22, 2018)

Great tutorial Matt! Thanks for doing this. Oh and if you need anyone else to test run one I can help with that!!

Reactions: Thank You! 1


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## Sprung (May 22, 2018)

Wildthings said:


> Oh and if you need anyone else to test run one I can help with that!!



After June, I may have a couple for sale or trade.

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## Nature Man (May 23, 2018)

Super informative! Looks like a coring rig is mandatory. One question early on in the process, how did you turn the tenons on the blanks? Chuck

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## Sprung (May 23, 2018)

Nature Man said:


> One question early on in the process, how did you turn the tenons on the blanks?





Sprung said:


> First you'll need to mark the center of each end and then turn the blank round between centers. Make a tenon on the one end to be grabbed with the chuck.


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## barry richardson (May 23, 2018)

Great post Matt! I might give that Foerster a try next time I buy..... that spalty one is going to be amazing.....

Reactions: Thank You! 1 | Agree 1


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## Lou Currier (May 23, 2018)

barry richardson said:


> Great post Matt! I might give that Foerster a try next time I buy..... that spalty one is going to be amazing.....



I bought one of those a while back and it did not cut well


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## kweinert (May 23, 2018)

I can see that I'm going to have to reverse chuck mine and epoxy on a new base so I can cut the tenon and finish hollowing. I was a bit short sighted when I glued mine up (segmented corian.)

Thanks for posting.

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## TimR (May 23, 2018)

Nice instruction Matt. Looking forward to finished pieces.

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## Sprung (May 23, 2018)

Lou Currier said:


> I bought one of those a while back and it did not cut well



That's a bummer, Lou. I've ran mine hard so far. Two of my drilling sessions were 6 or 7 blanks and I just went one right after the other, without giving the bit time to cool and drilling at a pretty good pace. I estimate it's drilled about 100" so far, all end grain. I know it'll drill more, but I can sense from the way it's drilling that it's starting to dull, so I'll touch it up with the diamond card before I use it next.

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## ripjack13 (Oct 4, 2018)

Matt, did you ever get pics to finish this topic?



Sprung said:


> Reserved for finishing & assembly.


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## Sprung (Oct 4, 2018)

ripjack13 said:


> Matt, did you ever get pics to finish this topic?



Not yet. I'm kinda behind on everything right now. Not just woodworking or shop stuff either. To say it's been hectic and that I've been extremely busy for the last several months would be an understatement.

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## ironman123 (Oct 4, 2018)

Thanks for the great tutorial. Those are some awesome turnings.

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## Sprung (Dec 28, 2018)

Updated above with the final steps! Click here to see them.

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## Eric Rorabaugh (Dec 28, 2018)

@Sprung 
Matt, is that 1st picture the spalted piece, the spalted maple I sent you?


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## Sprung (Dec 28, 2018)

Eric Rorabaugh said:


> @Sprung
> Matt, is that 1st picture the spalted piece, the spalted maple I sent you?



Nope - I haven't done anything with those pieces yet except rough them out and set them aside to dry. I hope to get to work on them sometime during this winter.

That really spalted one in there is a piece of Spalted Bigleaf Maple Burl that I got from @The100road - it was VERY soft and pretty much nothing, but I knew that when I got it from him and knew it was worth saving. Had to stabilize it. And spent a lot of time filling cracks. Was well worth the effort and it is my personal mug.

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## Eric Rorabaugh (Dec 28, 2018)

Its beautiful

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## Barb (May 16, 2019)

I just came across this post and it's perfect! I plan on doing one of these for a soon to be college student and maybe even one for myself even though I don't drink much coffee. Awesome build!

Reactions: Thank You! 1


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## Sprung (May 16, 2019)

These are lots of fun to make. I really want to make some more, and have been trying to find an excuse to do so, but have too many irons in the fire already. Hoping to this summer!

Make sure you post how yours turn out! If you don't have one, I highly recommend a hollowing setup - far safer than trying to handle far too much tool hanging off the tool rest.


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## Barb (May 16, 2019)

Sprung said:


> These are lots of fun to make. I really want to make some more, and have been trying to find an excuse to do so, but have too many irons in the fire already. Hoping to this summer!
> 
> Make sure you post how yours turn out! If you don't have one, I highly recommend a hollowing setup - far safer than trying to handle far too much tool hanging off the tool rest.


I am definitely going to try to get one of those set up first. I tried hollowing out a little lidded container and it wasn't pretty. That's when I decided to use a forstner bit.

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## Sprung (May 16, 2019)

Barb said:


> I am definitely going to try to get one of those set up first. I tried hollowing out a little lidded container and it wasn't pretty. That's when I decided to use a forstner bit.



Yeah, you'll want to remove most of the waste on these with a forstner bit first! I use a 2 1/8" bit, and have a link to the one I use within the tutorial.


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## Barb (May 16, 2019)

Sprung said:


> Yeah, you'll want to remove most of the waste on these with a forstner bit first! I use a 2 1/8" bit, and have a link to the one I use within the tutorial.


I've already put that in my amazon cart lol

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## Strider (Sep 25, 2019)

I love these!!

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