Toolmaking Art » Recipes

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

Best Way to Remove Scale, Is Not Having Scale!

Bob Strawn — Mon, 02 Mar 2009 13:00:00 +0000

Here is a bowl of goop. Below it is a blade I used the goop on. The blade was painted with the stuff, and then heated to a nice cherry red for about 15 minutes. Then it was quenched in safflower oil.

I had to put a cover on the oil, the oil caught on fire. No big issue, the oil was on some wax so the blade was suspended and able to continue cooling. The melting wax provides a bit of circulation, so for treating O1 it works out well enough.

I have not cleaned the blade off yet, but look how clean it is. No oxidation, no scale, no deformation. I will be treating my steel like this in the future.

The goop is a mix of boric acid, water and iron oxide. I mixed up about eleven parts of boric acid to one part of iron oxide. Stirred it around in water to make a paste. This stuff is great. Normally you have to remove the outer layer of steel as it has puffed up and become brittle hard scale.

Bob

Potting Mix

Bob Strawn — Tue, 02 Dec 2008 13:00:47 +0000

I garden a bit differently than most. Most of my garden is in pots. I do this primarily to conserve water. It also allows for easy weeding, plant isolation, and soil experimentation. Gardening in pots allows me to garden under trees. In my area, willow shade will reduce the brunt of summer quite well, making the garden enjoyable instead of unbearable.

The big expense gardening this way is potting soil. Not so bad really, the single month, summer water bill for conventional gardening vs gardening they way I am doing it, will easily pay for a years potting soil.

When I set up a garden pot, I try to use 3 gallon or larger pots. I stuff the bottom third with leaves to keep the soil from draining out with the water. Then I add my planting mix.

Here is enough soil to fill 20 3 gallon pots.

My mix Starts with spent mushroom dirt. For some plants, it end with that. My Celery loves mushroom dirt straight up. Daikon radishes will do fine in it as long as I supplement the potassium levels just a bit.

As a disclaimer, when you get a truck load of mushroom dirt, you often get a very rich smell. You can also get a bunch of flies for a while. This is a price I am willing to pay.

For potassium, I use Green Sand. This is 1% slow release. This maintains a decent level of potassium in the pots. This helps the roots develop, and makes the veggies better sources of potassium. In potting soil, potassium is usually the first thing to wash out. So a long term addition is a good thing.

Also quick to wash out of a pot, is calcium. Not having enough calcium will give brown spots at the bottom of tomatoes, blossom end rot, and will produce vegetables with less calcium. So for healthy plants and healthy people who eat the plants, a good calcium supply is needed. I try to incorporate some crushed limestone chicken grit. As you can see in the photo, I am almost out. This is nice slow release calcium. Not as slow as you might think however, it is often quite gone after two years.

For a quick hit of calcium or a dressing for plants, or to balance a low PH, I will used crushed agricultural limestone. The strainer is for spreading it on the surface of beds, and sprinkling on leaves. Some plants will absorb it from the leaves, and some insects, not as many as I would like, find it repellent.

A lot of plants will do fine in fine soil, but a lot of plants do better if they have a courser soil or more air space in the soil. This can be a problem, since the soil can dry out easily. Two common additions to soil can help give air space while retaining moist soil. Vermiculite and Pearlite.

Vermiculite

Pearlite

Pearlite is volcanic glass that has been heated under pressure. The sudden release of pressure makes it puff up like popcorn. This is fairly inexpensive if you buy it in a huge, yet far from heavy bag. It is still one of the larger expenses when you pot a lot. This is great stuff. I suspect the silica provided help some plants to be healthier and thus help us be healthier when living on them. I prefer to avoid it when growing root vegetables, as some can get included in the root and give a bit of a gritty feel to some root vegetables.

Vermiculite is a touch more expensive and not quite as light. It does not provide quite as good an air channel structure as pearlite, but it helps with moisture and nutrient retention better. For root vegetables this is a wonderful thing to add. I find I need to add more of it to get a good mix, than when I use pearlite. Vermiculite is Weathered Mica, that has been expanded the same way that pearlite has been expanded.

I always try to save a bit of mushroom dirt for later emergency use. The mound of mushroom dirt becomes a garden plot after it gets reduced to the right height, so by doing this, I don’t have to get as many loads over time.

Peat Moss is also a good addition, It increases the soils ability to breath, and acidifies the soil a bit. This can compensate for the calcium supplement added to the soil. It promotes the growth of healthy root in several ways, and helps give a good texture to the soil.

My standard mix is about 15 parts mushroom dirt, 5 of pearlite, 4 of peat moss, 1 of crushed Limestone, 1 of Limestone Chicken Grit, and 1 of Green Sand. This is usually done by the shovel full and mixed in a wheelbarrow.

I also take a 1/8″ screen and sift a bunch through it. The course soil left is great for growing. The fine stuff I save and uses as a starting mix for young plants I want to treat carefully.

Bob

Ozymandias

Bob Strawn — Wed, 19 Nov 2008 13:00:16 +0000

Here is my tomato pyramid.

It was made from willow saplings, and was treated with milk paint and borax. After that it has been out in the garden holding up tomatoes and other vines. It is about 11 feet tall and has done quite well. Light, sturdy, rustic and in it’s own way charming.

Sadly as I adjusted it today, it is quite apparent that it will probably last about one more year before it fails. Untreated willow lasts about two years in my garden. This pyramid will have survived but a scant five years.

This spring I will make another and will try my luck with a new treatment and see if it lasts a bit longer. I will try soaking it in borax and copper sulfate to preserve and color it green. It will start out blue, but will turn green over time. Then I will heat soak my wax mix into it before I assemble it.

Then I will put it in the garden to see how it holds up.

Bob