Toolmaking Art » Chemistry

Testing For Lead

Bob Strawn — Mon, 30 Apr 2012 12:00:10 +0000

In my pursuit of toolmaking, I don’t want others to come to harm. I use a lot of odd bits and bobs to make things with. Brass and bronze have a special appeal. The problem is that these items can be full of lead. Leaded brass is easy to work and polishes up with ease.

As long as no one looks over your shoulder or cares about the dangers, there are a lot of good reasons for a business to use leaded materials. Since compassion is only allowed in publicly traded companies when it is dictated by law, or demonstrably more profitable, it is just not safe to assume the products we buy are safe.

10$ and free shipping for 8 test swabs is a bargain considering that what you don’t know can make you and your children stupid and irrational. (Free shipping on $25+ orders, so you will have to get a few other items. Getting this marshmallow gun with it will still leave you 2 cents short.)

You take a swab, shake it up, crunch up the little glass containers inside the plastic sleeve, shake it up again with the swab pointed up, to mix the tiny shards of glass, powder and liquid, and then point it down and squeeze juice into the swap.

There is enough juice to drip some of the test fluid on a few objects and then swab with the remainder. This way you can test a few things at once.

I gathered a bunch of stuff I wanted to test and cleaned or polished or sanded a few areas on these surfaces. I also put the stuff that I thought would be safe first on my list to test. Once you have rubbed the swab on grungy or lead, you can not do further testing with it. You can however as long as it is still damp, clean and testing negative, keep checking stuff.

It comes with a couple of cards with lead spots so you can be sure it is working if everything tests out lead free.

The high speed sprayer nozzle, a long discontinued item from Harbor Freight, tested positive. The brass hose connector also discontinued, from Harbor Freight also tested positive, but not strongly.

This is sad, because both of these items are used for gardens, pets, yards and even children. It is also sad, because they would make great ferrules for tools. The little Stanley insert for opening sliding cabinets tested negative as did several other nice brass fittings. The old air hose fitting tested negative so it will someday be a very pretty ferrule.

These three pieces of brass all show red. The one on the left I was planning to use to make a tool today. This is the reason I started the lead testing. Now it is trash. I am not going to use it. The middle piece is a tube from a pen turning kit. Since the user will never touch it, I don’t have a big issue with the lead content.

Since the dust and shavings will be in my work area after I work it, I am going to have to come up with another way to turn pens. Otherwise I will be increasing the ambient lead in my work area, yard and on the products I make. The tube on the far right is a typical brass tube like you can get at a lot of hobby stores. Yes it tested positive. I will not be buying anymore of these.

I pulled off the sleeve on one of the test swabs so you can see the two glass vials inside. Make sure to crunch them up well and mix the ingredients. Note the scarlet stain on the trammel below the vial. Sadly this trammel tested quite positive.

I was worried about the small brass fittings in these pictures but they seem O.K..

The beautiful, functional and well designed trammels that I got from Rockler will never be used again. I really did not want this tool to fail. I just lightly brushed a whisper of the test fluid on the inside flat of the trammel.

The picture does not do justice to the lovely scattering of scarlet that matches with the lead test included with the kit.

This is really sad as this is probably the prettiest tool that I have ever bought. This trammel is perfect apart from the fact that it is laden with lead. I cannot use it, nor will I pass it on to someone else for them to use. I have tested brass fittings on 12 other tools and none of them came close to as high a reading as this trammel. I really liked this trammel set.

I probably would have put a thin coating of epoxy and then hard wax on it and just been careful if it had a low level of lead in it. Foolish of me perhaps, but it really is a nice trammel. This is not just a touch of lead however.

I guess this is another good reason to make your own tools. It is also a good reason to drink Kombucha Tea.

Bob

A Spherification Rack, A quickly made Fixture from Split Prone Cedar.

Bob Strawn — Wed, 18 Apr 2012 12:00:45 +0000

Creme De Menthe Caviar on Haagen Dazs Vanilla Ice Creme

Sometimes you need to do molecular gastronomy, and you need to do it now!

Spherification is a rather nifty process where you react juice with sodium alginate in it and a calcium containing fluid to make little juice filled gelatin balls.

While adding sodium anything to your diet should always be questioned, sodium alginate has been shown to help lower retention and absorption of lead, mercury, and some other bad stuff. Depending on your situation a little bit every now and then might be quite good for you. The entire reason I am doing this is to reduce the effect of some of my past exposure to lead and mercury. I have been a technician for a long time and have ample opportunity for exposure.

There are reasons to fear sodium alginate and reasons to want sodium alginate in your diet. Spherification is one way to get a small amount every now and then.

The basic method of spherification is to drop drips of sodium alginate bearing juice into a bath of calcium chloride. To make a lot of them quickly you need to be able to make a lot of drops quickly. One method is to make a spherification rack.

I needed it done within an hour, so I grabbed some wood that was handy and the right thickness. This particular cedar was a bit prone to splitting, so it has sat there for a while with no purpose, just because it was very pretty wood. Since this project is not going to do any serious load bearing, and it was handy, I grabbed this wood.

So I square my bevel with a 1-2-3 square. It tool longer to set up the camera than it took to square the bevel.

I use another board end and the bevel gauge to draw a base line on all the boards that I will dovetail. I mark with a pencil and with a striking knife. Then I mark dovetails and put squiggles in the area I am going to remove so I don’t make a mistake.

While I am showing methods of preventing splitting, I’m not going to actually teach how to make dovetails here, Paul Sellars does a better job of that than I ever could.
Learn Quick Dovetail Techniques with Paul Sellers

Here I come in with my carving gauge to make the lines a bit deeper where I am going to remove wood. This helps reduce tear out and splitting. I made the holes first using a 1″ forstner. The holes where laid out on a two inch center using a divider/compass to mark intersections.

I use two carving gauges, so that I can limit the cutting action in either direction.

I also like to define the end of a cut. This can reduce splitting.

In the image below, the saw cuts when being pulled down. No deep gouges are needed on this side to prevent tearout and splitting. The other side can get nasty however without a well struck line. This is a method for cutting dovetails without using a vise. In the case of this quick job, I was more concerned with speed than precision, so I didn’t even bother with using a vise.

Sawing lots of slits into the waste can also reduce the chance of tearout on split prone wood.

It is possible to remove waste by using just the carving gauge.

With wood this thick, a key hole saw is going to be a faster method.

The holes are drilled all the way through. I just haven’t punched out the biscuits yet. I drilled through until the point of the drill came out on the other side, and then I used that to center the drill and drill in from the other side. This is another good method to prevent split prone wood from tearing out.

With the project finished, I was able to complete testing on time.

I didn’t even clean up the edges on the finished rack. No glue, just a good combination of dovetails holding it all together.

With a board on top and gentle pressure, I was able to make a lot of ‘caviar’ quickly.

This rack has room to expand and it comes apart easily for storage. It does the job so well, that I am going to be putting up with this rush job for a long time.

My initial test told me that the rush was unnecessary, the flavor had a rather unpleasant tone that needed adjustment. So I did a bit more research.

First off, the recipes and methods out there on the web are for the most part ornamental and hardly gourmet. Seriously, there are better ways to do basic spherification.

The first thing to do is to replace the calcium chloride bath entirely. It makes the taste bitter/chalky and does nothing for you nutritionally. If you need to settle your stomach then maybe, but not if you want a delightful flavor. Calcium lactate barely has a flavor, and can be good for your teeth. It makes a much better caviar developing bath.

The second thing to do is to reduce the concentrations of the chemicals so you are working more with the initial flavors and less with the additional materials. The recipes out on the web are for the most part using way higher concentrations than are needed. The basic recipe that I give below may still be way more than what is needed.

First I premix a cup of distilled water with a gram of sodium alginate, and get a fairly thick syrup. I make this part ahead of time and keep it in the refrigerator.

When I am ready to make a batch of juice caviar, I put three tablespoons of juice in a cup and then stir one tablespoon of the premixed sodium alginate.

Then I make the caviar developing bath by mixing 15 grams of calcium lactate with three cups of water. This fills the bowl I use nicely. I have a stainless steel strainer and bowl combination that fit together perfectly so I can leave the strainer in the bowl while the caviar develops.

Here is the process, a drop falls from the food grade syringe, and falls into the bath below. The sodium alginate reacts to the calcium and cross links into an elastic shell. After 30 seconds to a minute, the caviar is ready to be lifted out so it does not immediately become gel all the way through.

As it sets the flavor is muted. If you have tasted jello juice before it sets, it is a much stronger flavor than after it turns to gel. The same is true here. So for the intense burst of flavor you need two things, the center to stay liquid and the flavor of the juice to be intense!

So My droppers run frantically for 30 seconds, I wait 15 seconds longer and then start to drain the caviar by lifting the strainer out of the bath. The strainer takes about 20 seconds to drain and then I lower it into a cold water bath to rinse off the developing fluid.

The next important step is to serve immediately!

A blend of amaretto, creme de coco and orange curacao makes an extraordinary burst of flavor!

Mixing in a few beads with raspberry syrup in with the liquor blend is also quite a joy!

Bob

Rotted Willow Smoke

Bob Strawn — Thu, 24 Nov 2011 13:00:41 +0000

Mmmmm. Rotted willow smoke!

It is Thanksgiving, and I am giving thanks.

At one time I planted several hundred willows.

These willows grew tall.

And they gave me lovely dappled garden shade.

This made for a very nice garden to work in!

Now, due to a shift in climate, all but a few are dead. In any case, when climate change gives you lemons …

Push over and dig up a few willow roots.

In it’s own way, a dead willow is still a treasure.

When you dig up a dead willow root, you get an amazing thing, Rotted willow root!

With some coals and a few scraps of willow root you can make the best smoked turkey in existence.

I don’t use petroleum to start my coals. The smell is horrid, and the taste is worse. Great barbeque does not start with petroleum distillates.

I like to use a starter tower. Since the handle broke on my old one, I quickly turned a new cedar handle. Nothing fancy, but better than the original.

In the foreground you can see a bunch of willow root chips. These will crumble about like weak cork.

I have lots of oak and it smokes really well. I have used hickory, and pecan and both of them do well too. I have mesquite growing in my yard, and prefer it to oak, hickory and pecan. But as long as I have rotted willow root, I have no interest in any other wood for smoking turkey, fish, lamb or whatever. Willow root makes for some yummy turkey.

Bob

Food Safe Glue

Bob Strawn — Sat, 05 Dec 2009 00:55:18 +0000

My next glue purchase is going to be a gallon of Ecopoxy.

I have been looking for a waterproof, food safe glue for quite a while. A lot of people advertise that their products are made with food safe glue, and a lot of people say that this or that glue is food safe, but when you research the final results, they don’t pan out. Some will talk about the safety of the product, but their web sites and literature don’t make the same claims. Just because a salesman has made a claim, and people believed it and repeated it, does not make it true. The only conclusive evidence of food safe glue, that I have found up until now is Tightbond III. It is rated for indirect contact with food. As a result a lot of people prefer it for making cutting boards.

Ecopoxy is currently not being marketed as a glue, but I think this will be just the thing. I have not tested it as a glue, but from the specs, it looks like it will be ideal. No glue is perfect, but this looks like a dream glue.

It has an unlimited shelf life. (heat may damage the resin) This by itself is amazing. An unlimited shelf life means you don’t have to replace it every year. You don’t have to worry that the glue you bought may already be three months old and only half as strong as it was. This is a big advantage. This puts it in the category with hide glue for longevity.

Probably using Knox Gelatin as hide glue is the safest glue you can get, but apart from peanut allergies possibly causing a problem while the glue is curing, or the BPA issue rearing it’s ugly head, this is as safe as any glue I have seen. It is rated for holding potable water, so food contact is not an issue. From the specifications I have read, I would trust this more than the plastic bottles or metal cans we drink from regularly. The metal cans are usually lined with this sort of epoxy anyway, and this looks to be the best of them.

The other advantages are reduced odor, VOC and environmental issues. Gluing up a boat in your garage would be quite a bit safer with this epoxy. This is made from soybeans, beans and peanuts, so the carbon footprint is much lower than most glues. The one downside is the curing time. It is typical for a glue to be fully set either overnight or a full day later. This will reach full strength in three to five days so for a rush job or impatient craftsman, this will not be ideal. A lot of the toxicity of finishes and glues comes from the materials used to speed the setting time, so I am not about to complain about the speed. I would much rather have safe materials.

Here are a few thoughts on usage. Cutting blocks come to mind immediately, but this product may allow for some really neat things to be made. Imagine taking 6 board feet of oak, and making a stackable one foot oak cube that holds five and a half gallons for brewing wine in. Or imagine gluing together three sections like the picture below and making a wooden flask. It would look really nice with a square cork. There is no reason at all that this flask is not triangular or round or whatever.

One neat application they list is using it with sand to make a non slip surface. A food safe, marine grade epoxy that is tough enough to use to as a floor coating sounds pretty wonderful to me. I want to make a cedar hot tub with it to put next to a small cedar swimming pool. Put that on a cedar deck, with a non-slip walking path and you have a pretty wonderful back yard. If you masked off a pathway, you could make a neat non slip path. This path could be intact or done as if stepping stones. I am sure you could do this with a lot of other epoxies, but I would feel much better soaking in a hot tub that was food safe!

I cannot give any advice based on personal use yet, but as soon as I can I will do an update on this. I have enough of a sample to do some quick testing, so I will be reporting on this as I go. In any case, this epoxy looks like a game changer.

Bob

Soap Making with Potassium Hydroxide, Part 1, The Process

Bob Strawn — Fri, 03 Apr 2009 13:00:08 +0000

I prefer to avoid pesticides, at times however I want crops and plants I love are being destroyed. One of the safer pesticides to use is soap.

Additionally I would rather add potassium to my crops, than sodium. Most soap these days is made from Sodium Hydroxide, it is cheaper and makes a harder soap. The old stuff was made with potash, Potassium Hydroxide. It costs a bit more, but for spraying on the tender leaves of my plants, I want a better grade of soap.

Potassium Hydroxide is still a dangerous chemical, and care needs to be taken when using it.

First things first, protective gear.

Vinegar is an acid that can be used to neutralize the Potassium Hydroxide, or KOH. It will quickly negate the alkali effects of KOH, but it will also produce heat while doing it. It is possible to cause burns while trying to prevent burns. To prevent this, the vinegar needs to be used wastefully as a wash and not as an ointment. KOH should be washed off with lots of water and then the residue neutralized with vinegar. Having a hose turned on and ready is a very good idea.

Safety glasses and gloves are also needed for safety. The area needs to be well ventilated, children and animals need to be elsewhere when handling dangerous chemicals. paths need to be clear, actions need to be rehearsed and considered. Contingencies planned for, I did this outside, in case I needed the hose to clean with.

Note that in this picture, the scale is not protected. This is probably not ideal.

In this picture, the scale is protected by plastic wrap, while the Potassium Hydroxide is being measured.

Here is the process, on a nice warm day, with a pleasant breeze and with no distractions or issues likely to arise, measure the water into a bucket and then measure and mix the KOH into the water. The chemical reaction of the KOH melding with the water is exothermic. Heat will be produced. Care must be taken, and the KOH must be added slowly. One of the many things you want to avoid is melting the plastic bucket while working with caustic chemicals. In my experience KOH is not as bad as Sodium Hydroxide for generation of heat, but being careful and aware of what is going on, is very important when working with these materials. The dust from KOH being poured can be quite bad for you. Bad for your eyes, bad for your skin and lungs. The vapors created when you initially mix KOH and water are also best avoided. So attention to detail and careful material handling are big issues.

I am using a cement mixer on a power drill to mix. When I actually pour the KOH, it is much closer to the bucket. I mix as I pour, so that the heat of reaction is not concentrated at the bottom of the bucket and instead is diffused through the rest of the water.

After the water and KOH have been mixed, you now have lye water and you want to start adding oil. The reason that I have specified a warm day is two fold. Oils pour better when warm, and need to be liquid to mix in any case. If the lye water temperature is lower than the temperature that the oils you are using stay liquid, you will have problems. If the mix falls below body temperature, it will probably not saponify. Saponification is the process of lye water and oil mixing and producing soap. This reaction may or may not instantly happen, and may cause you considerable stress getting it to happen. Agitation and warmth are key to making it start. Sometimes it will start and stop. In some cases it will take a long time. In any case, soap does not cure as well or at all when cold.

Here is the mix I made, Water, KOH, Soybean Oil, Palm Oil all carefully measured and added. Now I see a problem. The bucket is too full to mix well. I made too much. So I carefully mixed it up and then removed a bit, to try and keep the mix even. If I just removed the lightest materials on top, I am sure to mess up the recipe.

Here I am mixing the stuff. Note that a bit has spilled, and that the small bucket beside it has separated out. A sure sign that it has not reacted and made soap.

Finally you can see that the goop has started to gel. This is the sign that it is beginning to be soap. Notice that the shadows are getting longer. Sadly a cold snap was coming in, and part way through, the gelling stopped. I put the raw partially reacted soap in my green house and the next day when the mix was nice and warm, it quickly mixed up and made soap. Fortunately my poor timing did not result in a bad batch.

Usually you wait for two weeks or a month before using the raw soap. You also make sure there is not lye left over that has not reacted. To avoid this your recipe is usually five to ten percent super fatted. That means that more oil was used than was needed to prevent making skin damaging soap. Since I was not worried about making a hard bar of soap, I used extra water. This helps to prevent all sorts of possible issues. It also speeds the reactions.

Here is the horrible test that I use to see if my soap is going to be harsh. Before I tell it to you, please remember that I do not advise anyone to be as crazy as I am and use my methods. A strip of litmus paper is a much better way to go. I just like to do it the way the old timers did, I taste my soap. If it does not burn my tongue, then it is not caustic. This is not a compliment to the soap really, but this was, hands down, the best soap I have ever tasted. I still washed my mouth out with water.

Bob