I am almost finished construction some raised beds to start thicket bean (perennial) in out of cedar. I can apply a slight slope to the top, to help it shed water, and I could apply laminating epoxy to the points where the corner posts touch the ground to reduce endgrain water penetration. But, I was wondering about a finish for the wood.
I live in Canada.
Anyway, I ran across a blog which talked about a different treatment. I think the company is Timber Pro, out of Oregon. They have a wood stabilizer, as near as I can tell it is only available in the USA. Between the blog and the web site, I thought there might be enough information to track down what is happening.
I believe this product is a kind of (potassium) silicate mineral paint (a product in the cement industry), which reacts with calcium (maybe magnesium as well?) in the wood, to cause the product to "harden" inside the pores of the wood. This product is nominally a water based product. Apparently a couple of coats will "permanently" treat the wood. Such treated wood no longer absorbs stain anywhere near like what fresh wood does. It is supposed to take paint well. I suspect that coating to rejection might be effective, similar to how paper was repeatedly coated with phenolic resin to produce honeycomb core for composites work.
Has anyone run across some non-IP entangled recipe on this (or similar) idea?
Why not use short lengths of steel pipe from old street signs?
John Daley Bendigo, Australia
The Enemy of progress is the hope of a perfect plan
Location: Dawson Creek, BC, Canada
posted 1 year ago
This spring, I have built 4 small (2x2 foot) raised bed planters, and I am in the middle of making 4 3x6 cold frames.
The raised bed planters are all western red cedar. One of these planters has had one "edge" planed to shed water, and it was shellaced all over. Giving two (or more) coats to end grain. Shellac should stand up to water fairly well, as long as that water does not contain an alcohol. So, no beer drinking in the garden. If you set a hot cup of coffee on the planter, a "water stain" may result. Shellac is supposedly brittle, so don't beat on it with a hammer. If you need to repair the coating, the alcohol solvent in the liquid shellac will "melt" the shellac on the surface, allowing for a good bond of new to old.
Shellac is apparently somewhat UV resistant. Modified shellacs are known, but I had never heard of any before today. One modification that seems useful is with maleic anhydride.
Where I am, the only shellac you can buy (pre-made) is small 1 litre cans. So, the above work was done on that single can, with some left over. Shellac flakes (waxed or dewaxed) are still available. To make shellac, you just need to add "alcohol". The flakes are a natural product (of the female lac bug from SE Asia). You can use methanol, ethanol, propanol (typically iso-propyl) and probably other alcohols (probably glycols, and so on). By and large, alcohols absorb water, and having some water in the shellac doesn't interfere too much with using it for a varnish or finish. So you need not be looking for anhydrous alcohol.
Methanol is toxic. I've seen many write ups about how cheap isopropanol is, I guess they were smoking something when they were looking at prices. Where I am,methanol is the cheapest alcohol in general, if you buy enough of it. I am in Canada, prices where you are could be completely different. But there was no relationship between container size and price. To go to larger containers could result in a larger unit cost. I even seen volume "increases" in cost.
I have an unrelated project on the farm, where I want to "temporarily" cover a deck (joists on 12 inch centers) with 5/8 OSB. I am planning to "paint" shellac on all sides of the OSB. I am guessing I will need about 12 litre of alcohol. The cheapest I could find, was to get 24 450 ml bottles of 70% denatured ethanol. The order was accepted, but the product has yet to arrive.
In terms of UV resistance, I haven't researched it enough (yet), but I suspect that shellac has better UV resistance than wood or epoxy. But in terms of using it on wood to protect the wood from UV, you probably would need to apply many coats. I think the UV resistance is better thought of as the properties of the shellac should not degrade very quickly with UV exposure.
I think some shellacs have been combined with acrylic resins (which are also UV resistant to some degree), but again I don't know enough.
I finished one cold frame, where the "2x2" corners are cedar, the bottom 2x6 are cedar and the top "window/door" is 1x4 cedar. Everything else is ordinary construction grade SPF. The bottom of the cold frame was shellaced, the inside vertical surfaces were shellaced, the bottom cedar board was shellaced on the outside and the bottom board of the "top/door" was shellaced. And that is where I ran out of shellac.
People writing about making cold frames have said a good seal is necessary (top to body), but I have not seen any HOWTOs where caulking was used. I ran across a spruce 2x6 which was bent a little, and I had two part of the board in different orientations, and a significant gap between the two in places. I used a sander to "reprofile" the top board, and I will caulk the joints on the outside (so that caulking doesn't contact food growing conditions). I think some kind of weather stripping of top to body is needed, but recommendations on that didn't seem to be in any HOWTOs. Temporarily place some wax paper on the underside of the top, and then apply a bead of flexible (such as butyl rubber caulking) to the top of the body, and close the top (lightly?) until the caulking cures?
For both the raised beds and the cold frames, I am using western red cedar "2x2" for the corners. Nobody here sells cedar 2x2, these are pieces ripped from larger 2x cedar lumber. You need to be careful in inserting screws into cedar (as the "anchor" of a joint), as it is low strength and you can strip the "threads" quite easily. Another consequence of the "low density" of western red cedar with respect to other woods (SPF or hardwoods), is that it is more flexible. So, if the 2x boards you are making a cold frame out of are not perfect, the cedar 2x2 corners will adjust to try and "best fit" the corners. My first cold frame wasn't exactly square (because of issues like this), but it is close. I think this flexibility property is probably useful with other woods, especially woods which are quite a bit harder. It may be that a 2x2 cedar corner is not big enough, to work for stronger wood boards. You might need to go to 3x3 or larger. This is so that you can use longer screws, and spread the load over a larger region of cedar.
On my farm, I have a need to start replacing tamarack fence posts at some point soon (they could be 80 years old, more?). So, I am planning to set up some arrays of Osage-orange, black locust (and honey locust) to grow fence posts and corner posts. I am hoping that the Osage-orange and black locust can produce fence posts in 4 years on the first iteration, and then every 3 years after that.
I gather fence post bundles are sold in terms of a number of posts in a bundle. It seems to be more than 100 posts. If I plant an 11x11 array of either Osage-orange or black locust, that would ideally mean 121 fence posts on a harvest. I am not sure if the first harvest is all I need, or if I need part of a second harvest for my own purposes. But I was thinking that after my own needs have been met, I could produce 1 bundle every harvest, and then auction them off.
I am planning to have two arrays of Osage-orange and black locust, to produce "corner/gate" posts. These need to grow longer, but I don't know how much longer (yet).
I have read suggestions that while honey locust is not as durable as black locust (or Osage-orange), it is still fairly resistant. So I am hoping that a person could grow it in an array, probably for longer than the corner/gate posts require. For my farm, the object is to grow them to the point where I can get a rough 2x6 out of the tree that is 16 feet long. But since most of that need is for fence boards, the boards would not be machined as rectangular. They would be "tilted" a little, so that water would not collect on the top. I would plant a large enough array, that I can replace the finished SPF boards that fail due to rot or deer. Just on the basis of cross sectional area, the rough 2x6 has 45% more cross sectional area than the finished 2x6. That honey locust is probably stronger and stiffer than SPF is an additional bonus. After some number of cycles, all the fence boards will be rough honey locust, and a person could continue to run the array to sell similar boards to other people.
Some cold frame HOWTOs mention placing a layer of (foam) insulation on the inside surfaces. Often they comment that this extends the life of the cold frame.
The purpose of the cold frame is to regulate the environment (temperature/humidity) on the inside. In a mixed insulator and thermal mass system, the thermal mass goes on the side seeking control (the inside). I have no doubt that insulation will help, but it belongs on the outside. If you want to protect the inside from the humid/oxygen rich conditions, that is what a finish on the interior wood surface is for. A paint could work (as paint is meant to restrict water vapour transport), or a varnish or a shellac. Putting a "layer" of foam insulation on the ground surrounding the cold frame, will make the thermal footprint of the cold frame bigger, which will cause more heat flow from the centre of the Earth to divert to pass through the inside of the cold frame. To put a 2 foot wide foam around the perimeter of a 3x6 foot cold frame multiplies the thermal footprint by almost 4.
But just wrapping the outside of the cold frame with foam will help in a couple of regards. If you didn't caulk the outside board joints, the foam will reduce air infiltration. The foam/ground interface may stop some species from going into the cold frame (slugs, ...). Some people have had problems with moles, I doubt foam would stop them. You may need to put wire mesh at ground level to stop some unwanteds from entering the cold frame at the bottom, or from underneath.
Location: Dawson Creek, BC, Canada
posted 1 year ago
Valhalla is a Canadian company, I should be able to buy it here.
What is it, what does it do and how does it work.
The website to me is mysterious. This product has been around a while, and I happened across a Fine Homebuilding thread on this.
Lots of transition metal ions are good at absorbing UV. It seems likely that this Valhalla product is mostly ferrous sulfate, so it is the ferrous ion. So, Valhalla is likely ferrous sulfate and other stuff.
It may be that high concentrations of iron in things could reduce rot. Valhalla seems to have a high herbal content, and maybe some of those herbs are high in things like boron. Boron compounds are known to reduce rot; but they tend to be water soluble and wash out. Some wood products on the market have been acetylated (reacted with acetic acid). To me, this could vaguely be "poisoning sugars". But, is some mix of herbs we might find in any Italian kitchen going to acetylate wood?
There seems to be a lot of "hocus pocus" to the product. It may work and they may not know why it works.
In terms of ground contact such as fence posts, you can get "slugs" of a boron compound meant for fence posts. At about ground level, you drill a hole into the post where the end of the drilling is about the centre of the post. You "drop" a boron slug into the hole (and maybe push it to the bottom). And then you insert a plug into the hole, to seal it off. Periodically, you can probe the hole, to see how much of the slug is left; and when it is gone you insert a new slug of boron (it might be the sodium salt of some boron compound).
Covering the tops of wood structures such as posts, beams and joists so that water can't wet that top surface, goes a long way in durable wood construction. For things like decks, where boards are supposed to be almost level, having some slope from the centreline is better than no slope on the top surface. Milling a drip edge on the underside (which is never seen) will reduce how much water can "walk" along the underside to wet some vertical wood element supporting the deck board (or railing).
If you are building a board fence, normally one applies boards with a rectangular cross section to the fence. Tilting that rectangle by 10 degrees so that water flows to the side away from the post will reduce how much water gets into the joint between the board and the post, and it allows the tops of boards to dry much faster.
You could just plane the top surface of a rectangular board, but if the bottom of the board is not treated similarly, water will "walk" the underside to wet the post/board connection at the bottom. And that is enough to rot out things. To make the trapezoidal board instead of the rectangular board automatically puts a "drip edge" on the bottom outside, so that no water walks along the board to wet the board/post connection.
Treating wood (or picking wood that might be durable) still seems to have aspects science hasn't pinned down.
That feels good. Thanks. Here's a tiny ad:
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