Sunday, July 29, 2012

Screw Boxes and Wooden Threads

Finished Product

Threaded wooden screws can be incorporated into a multitude of tasks and tools. In an earlier post I showed a plow plane I constructed utilizing wooden screws for the fence adjustment so I thought it would be an interesting post to explain how easy they are to make.

First a screw box and tap is needed. The one shown here I ordered from Woodcraft several years ago. I also have a router driven set from Beall Tool that makes outstanding threads.  Next suitable wood is needed. Use fine grain straight stock. I’ve used hickory, maple, yellow birch, and even cotton wood which I don’t recommend. The best wood by far is persimmon and it’s the wood I used for this post.

Rough Blank 
The screw I made in this post is ½ inch diameter. I planed the wood down to just a bit above a ½ inch and cut the wood into the shape of a ‘T’. Next I carved the lower part of the T into a shaft. This really isn’t hard. You could use a lathe to turn out rough blanks and I do for larger screws, but for the small stuff this is the most efficient way. Don’t bother carving the head of the screw yet. If your threading doesn’t turn out you haven’t wasted any work.

 I checked that the diameter of the shaft is correct by testing its fit through the guide block on top of the screw box. Some wood can be made to thread easier with a lubricant like mineral spirits. The persimmon I used didn’t need it.    

Guide Block On
The first threading I did was with the guide block on. With this screw being short I needed to back the screw out and remove the guide block so I could cut threads closer to the head. It’s also a good idea to make your threads longer than you need, you can cut the excess off later.

Next all that’s needed is to shape the head. I will cover tapping the screw hole in a following post that will detail how I make my marking gauges. 

Guide Block Off

Monday, July 23, 2012

Butter Churn

My churn is 10" excluding handle by 5.5"

Butter is not a bad word! Unfortunately those crazy scientist’s and medical doctors say we should go easy on it. Use it more like a condiment or just don’t eat it at all. Tell that to our forefathers who slathered it on everything they ate.

Interestingly the production of butter goes back some 4000 years. Butter was a way of preserving the byproducts of milk much like cheese, and was a valued food source. Ever hear of Bog Butter? They still find this stuff buried in peat bogs in Europe. Some of it is edible after 3000 or so years. Now that’s what I call long term storage! ( I think I might have been served this stuff in the service)

Bog Butter
I've wanted to make a butter churn for a long time, but could never decide on a design. Then one night I spotted a neat table top churn on eBay. Not too big and probably 18th century in origin. This was what I’ve been looking for. I never made any kind of coopered container before, but I really didn’t think it would be that hard. Wrong! I tried to do it with hand tools, but after two egg shaped failures. I decided to make a jig for my table saw so I could get a consistent angle and taper. The rest of the shaping was done with hand planes and spoke shaves. It took a lot of adjusting to get it water tight and even now I have to soak it in water so the staves swell up to hold liquid.

Original churn 
Making butter is not hard. All you need is cream, pasteurized is fine in fact I wouldn’t recommend raw cream due to safety concerns. Let the cream set out for 12 hours this gives time for the good bacteria’s to start producing lactic acid. The lactic acids weaken the cells of the milk fat and allows the butter to churn (congeal) easier. Basically the milk fat is contained in little vesicles that get popped like a water balloon by the action of the dasher. As the containers are broken the fat congeals and becomes a big mass separate from the byproducts referred to as butter milk.  

Everything ready to go the water in the churn
 is just to keep the staves tight it get dumped out
before the cream is added
Next you work the dasher at a gentle pace, about 12 min for my churn. After the butter fat has congealed you need to rinse it with cold water to get rid of buttermilk. If you don’t get rid of the buttermilk the butter will get rancid. In historic times a small amount of salt would be added to help in the preservation, but you really don’t need it if you’re going to keep it in the refrigerator. Your butter will most likely be white as the yellow in modern butter is food coloring. Natural yellow in butter is caused from carotene in the grasses the cows eat so it will depend on the time of year and type of feed the cows consume. It all tastes the same in the end.    

About 2 cups of butter from 1 quart of cream
The butter after it has been washed and salted

I know my instruction are vague, but it's just something you have to experiment with. If you’re interested in making something like this I recommend the book “How to Make a Coopered Bucket” by James D. Gaster. The third edition of Fox Fire has good information as well. Robert Krampf has a good tutorial on butter making on YouTube follow the link.