Greenhouse construction begins

[GpsFrontier]

The last week has been filed with obstacles. I was able to finally get about all the "cull' wood I needed. But I have had regular weather problems with wind and rain every other day. As well as a issue with the rubberized coating I planed to use for laminating the plastic sheeting to the OSB not having good contact. I do have (come up with) another economical option, but wont post anything about it until I have tried/tested it and seen the results. But so far it looks promising.

I have pictures I have taken over the week, but they aren't downloaded to my computer yet, and it's 3:35 am now (and I still need to make dinner), so I don't feel like doing it right now. But will definitely post all the pics later. Just thought I would make a small update.

Also I have some consecrations for heating, but at this point I'm mostly back to looking at "propane" options. I can elaborate later on the options I'm looking at. But so far the small camping heaters still look like the best option. All the other options (even under $100) put out too many BTU's (30,000-50,000), not only wasting the propane, but even more importantly would likely damage my plants in such close quarters. Even if they were on timers and/or a thermostat, unless the heat could be dispersed differently.

[GpsFrontier]

OK, I finaly have the pictures downloaded to post. Now that the hydroponic system support structure is finished, I have been working on building the hydroponic systems. To do that I need to laminate a lot of wood with the 6ml plastic before I can put it together. In total I need to laminate 24-2x4's (8 foot), 60- 1/2 pieces of 2x4's (the cull wood) I'll cut them to size later, 12-3 feet by 8 feet sheets of OSB, and 9 more sheets of OSB (about one square yard each). As of tonight, all I still need to laminate is 36-1/2 pieces of 2x4's (the cull wood), and 6 of the small one square yard sheets of OSB. The rest is laminated. So most of the pictures are of the process of laminating the wood. I hope to be able to get the rest of the wood lamination done tomorrow (baring weather problems, and/or needing to run back out to Lowe's for more contact cement which is almost a certainty).

By the way, the alternative I came up with for laminating the plastic sheets to the OSB is working very well. I decided to use "vinyl tile adhesive" But you've got to be sure not to get the stuff for feltback vinyl tile, and get the stuff for vinyl composition tile (VCT). This is the exact stuff I'm using: HENRY 430, 4-Gallon Vinyl Tile Adhesive. It's very sticky with the consistency of something like a thick elmer's wood glue. I'm using the smallest notched trowel I could find for spreading/applying it to the OSB. Once it's applied to the OSB, I just roll out a pre-cut piece of the 6ml plastic sheet and just use a dry rag to push out any air bubbles for a clean/even lamination. It will take a good 24 hours for the tile adhesive to cure/dry, but I'll give it a minimum of 48 anyway. It does seem to want to make the OSB bend/bow as it drys, so I've placed them face down on the garage floor, and placed a lot of weight on top to press it down (the 5 gal buckets you see are full of water). I got 2 boxes of the 4 gal size of the adhesive ($27 ea), but in total I will probably only need about 6 gallons total to laminate all the OSB I need to.

Not sure if I mentioned this earlier or not, but I'm using contact cement for laminating the 2x4's. It's a simple process, but kind of boring. I first cut one foot wide pieces of the 6ml plastic from the 20 foot wide roll, then cut them into 10 foot long pieces (I pre-cut about 50 of them). To laminate them I just roll them out the table, wash them off with a wet rag and let dry. Then I roll on a coat of contact cement to one side of the 2x4's, and then to the plastic sheets. Wait 10 min, and apply the two sides together on the table. Then I apply contact cement to the rest of the surface of the 2x4's and wait another 10 min before rolling it over the plastic sheet and pressing it on using a dry rag as I go. To make the seem, once all the sides are done I apply a more contact cement to the bottom edge and cut the plastic edge so it overlaps the bottom edge, but the seem stays on the bottom edge and wont wrap around (sorry I forgot to take pictures of that part, but will try to remember later). When I construct the hydroponic system, that will be on the bottom edge and wont come in contact with water, so water cant get inside the seem.

In case anyone is wondering why I don't just use the contact cement on the OSB as well, there are two reasons. First it would simply be to expensive, the contact cement is $30 a gallon, and I would need about 8-9 gallons for the about 450 square feet of OSB I need to laminate (costing in excess of $250, verses the $60 for the vinyl tile adhesive). The second is it would take at least 3 people to apply the plastic to the OSB once they were coated. If it's not attached perfect the first time, I' screwed. Simply because you cant redo it (once it touches it's stuck), and for the same reason you cant just roll up the plastic sheet to roll over the OSB once you apply the contact cement, or it will stick to itself.

P.S.
Notice the borders I made to keep dirt from falling into the sub "T" system. I just used a flexible flower bed boarder, and screwed the end's together, placed them around the sub "T" system lids, and back-filled around it. I couldn't stake them down because of the high likelihood of the stakes going through the tubing. Also if my beard looks funny, it's because I tucked it inside my shirt so it wont get stuck to the contact cement.

[CrossOps]

GPS that looks awesome. I had not idea you were constructing this, this way, perhaps I misunderstood you when we talked. This is pretty slick. Any idea on the longevity increase utilizing this method of coating/covering the wood?

[GpsFrontier]

I'm not sure what you mean by "longevity increase". But as far as constructing the hydro system, it's important to make sure you don't make holes in the plastic during constructing it. But as far as the overall projected longevity, I can tell you the 6ml plastic is construction plastic that is used in all parts of construction. Including being a moisture barrier and intended to last many decades. As far as the "contact cement" longevity, that to is intended to last decades, it's typically used for laminating counter tops and similar cabinetry. As far as the OSB longevity, it's the main wood used in house construction. As long as it's kept from moisture it will last a century or more, if not it can decay immediately if the wood is saturated.

Of coarse the vinyl tile adhesive is also intended to last for decades, being used to adhere tile to floors. The particular "VCT" adhesive is mostly used in commercial buildings, including hospitals. However the vinyl tile adhesive is only water resistant (not water proof). So that means it's water soluble and that you need to pay attention if you damage the 6ml plastic. But depending on how bad the damage is (pinhole, scratch, tear, etc) it can be simply patched various ways (silicone, hot glue, marine goop, etc.), and it would only be a problem if was below the water line in the system.

[GpsFrontier]

Well I took some more pictures today of how I'm laminating the 1/2-2x4's. Some of the pictures are redundant, being that they show the process of laminating the wood with the contact cement from the beginning, and I have already posted similar pictures. But heck, I may as well post them too because I have them. Though I mostly just wanted to show how I made the seems on the bottom edge I mentioned in an earlier post.

Basically once I've laminated all 4 sides, I fold back the overlap, and tape it back with electrical tape. Then I wash the dust off the bottom edge with a damp rag and let dry. Then I brush on a coat of contact cement to the bottom edge with a disposable foam brush, as well as the rest of where the plastic will overlap, and on the overlapping plastic itself. Then just fold the plastic back over and press it down firmly using a dry rag. Then I just cut off the excess overlapping plastic and press down the seem. I haven't bothered to clean off the excess contact cement from the bottom edge, I don't think it's any problem at all. But I already have a new bottle of "acetone" nail polish remover to do that with if I decide to later.

P.S.
You may notice on some of the shorter 2x4's, the plastic lamination dosen't go all the way to the end of the board. That's because the table I'm using has a 8 foot long work space, and some of the 1/2-2x4's are longer than 4 feet. So sometimes some of it hangs over the edge. But these boards will be cut to size later, and I will need to cut off anywhere from 8 inches, to a foot and half. So the couple of inches at the end that didn't get laminated in plastic will be cut off later anyway.

[GpsFrontier]

Just a little update on greenhouse heating options. Well first off I'm still skeptical on using electric heaters, but after running some numbers it may not be as bad as it seems if my numbers are correct. I was at Lowe's today looking into their propane heaters and after asking some questions (and reading the box), I was interested in a heater like this: Shop Mr. Heater Buddy Heater at Lowes.com. The particular one I was looking at was rated between 4,000 and 6,000 BTU's. The box also stated that it would run up to 110 hours on a 20 lb tank. Of coarse that would be on the low setting (4,000 BTU's), but doing the math and assuming a 20 lb tank refill would cost me $20, it would cost about $0.18 per hour to run ($20.00 divided by 110).

After looking online at some electric heaters for cost comparisons I found this one: Shop :USE 2-in-1 Convection and Radiant Heater at Lowes.com. It runs 1500 watts on high, and says it puts out a maximum 5,100 BTU's. Now to compare them I know we pay $0.09.29 cents per kilowatt hour, and using the Electricity Cost Calculator I compared running the electric heater for 110 hours. So 9.29 cents, and 1500 watts shows it would cost $15.33 to run it for the same 110 hours ($0.14 cents per hour).

Going by those figures the electric heater should cost less to run by 4 cents per hour. However I have always known gas and propane heaters to be more energy efficient. But of coarse there's always the variable of the fluctuating propane prices depending on where you get the tank refiled. Though on the other hand it's much easier to thermostatically control electric heaters than gas/propane heaters. Well, at least for a small scale greenhouse setup, rather than a household system anyway. And being able to adjust the heat, as well as how much fuel is burned is necessary in being energy efficient (cost effective). With that in mind, I think the key in being cost effective is really going to be being able to adjust the heat level as needed (fuel or electric). Also if using a electric heater I would suggest having a "Kill A Watt" meter to make sure you know how much it's costing to run for sure.

[GpsFrontier]

Well I thought it was time for an update. I've been so busy building the hydroponic system growing beds, that I just haven't had much time for anything else. There are more than 20 pictures, so I'll break the update up into two posts.

In total there are 21 grow beds, 12 of them are approximately 8x3 foot grow beds (large ones), and 9 more about half that size (small ones). After all the wood was laminated with the black plastic it was time to start constructing the grow beds. First I laid out the the laminated OSB face down on the table. Then I screwed in the laminated 2x4's around the sides. Once all the screws were pre-drilled and screws screwed in, I unscrewed 3 sides. That way I can keep all the holes lined up. Once I unscrewed the 3 sides I lifted the OSB and placed blocks to hold it up.

With the OSB up and out of the way, I hot glued the corners and ran a bead of 100% silicone along the inside seam between the OSB and 2x4's. Once I did one side, I screwed that side back down, and did the same for the other side, then screwed all the screws back in. Then I flipped the grow bed over and finished hot gluing all the corners from the top until the seems and gaps were all filled in. Then I continued to hot glue the outside seam all away around the grow bed, to stop any leaks that may get passed the inside silicone bead. Once all the hot gluing was done, I ran another bead of silicone around the inside edge of the grow bed.

I also finally took some pictures of the parts to my water filtration system. I have had them for weeks, but just took pictures of it today. There are 4 different replaceable cartridge filter housings. First will be a sediment filter, then the 1 micron filter, and then two carbon filters. The cartridge housings were $19 ea, the sediment filter was $9 (for a 2 pack), the carbon filters were $13 ea, and the 1 micron filter was $22. If you look closely at the 1 micron filter it shows it is a 0.5 micron filter. But with the allowable variance of .5 microns, it's really the same as a absolute 1 micron filter.