When I was asked to make a cremation urn for my nephews dog, I had to figure out how to be sure the urn was going to have adequate capacity to hold the dogs ashes. Here is what I learned after a great deal of searching and trial and error. I hope this will help you avoid all of the research time I spent on line.

The volume of cremated ashes, no matter if they are animal or human, is the same. You need 1 cubic inch of space for every 1 pound of live weight. For example if the dog weighed 23 pounds you need a volume capacity in your urn of at least 23 cubic inches. I would allow at least 5 cubic inches for comfort.

The next problem is determining how big your piece of wood needs to be and how do you tell how many cubic inches are inside of your hollowed vessel? This is how I figure that out. There are 14.44 cubic inches in 1 cup, so you need 1 cup of space for every 14.44 pounds of live weight. I found that rice works great to determine capacity. Buy yourself a 2 pound bag of rice and keep it in your shop for measuring. Take the weight of the animal for example a 30 pound dog and divide it by 14 to determine the number of cups, 30/14 = 2cups with 2 cubic inches left over. One tablespoon equals about one cubic inch so take a baggie and pour 2 cups and 2 tablespoons of rice into it. Squeeze out the air and now you have something that will give you a pretty good idea of how large a piece of wood you will need to hollow out this much volume. When you are hollowing and you think you are getting close to the size you need, remove your chuck from the lathe leaving the urn attached and stand it upright. Pour in the rice. If the rice fits in the urn with a little room to spare you’re there. Remember to leave a little extra room as most people know about how much their pet weighs but probably not exactly and you would not want them to come up short when they transferred the ashes to the urn, so error on the high side. Also make sure you leave extra space for your lid if it glues into the top or bottom.

If you are going to get into urns and plan to sell them, you should also know that many states require that the lid of a Cremation Urns needs to be threaded.

See the tips section of this site for instructions on Making Easy Threaded Inserts for a simple way to accomplish this.

If you want to try hand chasing threads, I would recommend that you ask your local counter top company for some Corian cut off scraps as Corian is one of the best and easiest materials to chase threads in. Most cabinet shops are more than willing to give you some scraps. You only need a couple of pieces about 4 inches square depending on the size of the hole in your urn. I would get a couple of spare chunks though to practice with. If you do get corian cut a circle larger than you need on the band say and then use hot glue to glue it to a waste block to turn it. From that point on you just follow the same instructions you would use for wood and use the same tools.

My second recommendation is for you to view the 3 youTube videos by the Wyoming woodturner . They are titled THREAD CHASING : HAND CHASED MALE THREADS IN WOOD PART 1 THREAD CHASING: HAND CUT FEMALE THREADS IN WOOD PART 2 and THREAD CHASING: MATING FEMALE AND MALE THREADS These are excellent videos and will have you chasing threads in no time. One thing to mention is that he has changed his opinion on speed and now recommends that you turn at around 300 to 350 RPMS when you chase threads.

I hope this helps you out and answers some of those questions you may have.

Cindy Boehrns