Interesting tip for building coldframe

I just read "the  new organic grower's four-season harvest" by Eliot Coleman. It was good and he had a good tip for building coldframes. Build 2 at a time. When you nail a triangle to a straight board you don't get a lid that is level with itself. I"ll draw a pic to clarify.

The basic build is to make a box, then cut at a diagonal on the ends. This turns it into 2 coldframes. The cut side goes down. You have a perfect top on each one for applying the glazing or a lid.

The only downfall is the side walls do not go straight up.

Here is the small problem it corrects. The back wall of the coldframe sits higher than the sidewall that intersects it.

How does one cut these without a spiffy tool like you have pictured? Could I do it with a bow saw?

If I had my ruthers I'd heat my cold frame using Bill Haynes's idea of a sunken pipe, elevated at one end:

Bill Haynes wrote:...If your up for some input.... 60 watt halogen bulbs in series for heat..
Halogens create an extraordinary amount of heat for wattage input, wired in series they last forever because they are so far below their max power constraints, they are available cheaply everywhere!...

Burl, everyone,

If I had one of those little annoying edges sticking up I would use my multi-tool.  Mine is from Ridgid and can be found HERE:

https://www.homedepot.com/p/RIDGID-18-Volt-Cordless-JobMax-Console-with-Tool-Free-Multi-Tool-Head-Tool-Only-R862005/300232326.  

I would use a semi-circle cutting end.  Basically it is a little vibrating cutting tool and will slice through wood like butter and is ideal for oddly shaped or angled cuts.

BTW, while I can recommend the Ridgid variety, I am not recommending it exclusively and if you can find a better deal or another manufacturer, by all means go for it if you think it will work for you, especially if it is at a better price.  But one of these tools is pretty handy to have for a situation like this.

Alternatively, a reciprocating saw would likely cut off the angled piece just fine as well.

Good luck,

Eric

Fantastic tip, thanks!

The only downfall is the side walls do not go straight up.  

Can you elaborate?

I am seeing the two cut frames in the picture, and it looks like the one on the left would set plumb because it was the bottom frame. If you turned the right-most frame upside down, would it not set plumb as well?

Stacie Kim wrote:Fantastic tip, thanks!

The only downfall is the side walls do not go straight up.  

Can you elaborate?

I am seeing the two cut frames in the picture, and it looks like the one on the left would set plumb because it was the bottom frame. If you turned the right-most frame upside down, would it not set plumb as well?

I'm guessing rather than side walls, he was referring to the front and back walls that are no longer straight up after flipping.

Nicole Alderman wrote:How does one cut these without a spiffy tool like you have pictured? Could I do it with a bow saw?

I'd just use a circular saw. But would probably have to raise the end a bit to get the part close to the ground.

With the right tool it is easy to make the diagonal cut to turn one box into two. (I would use a circular saw as that naturally makes clean straight cuts.)

There is no point in doing the extra work to bevel the top edges of the back to get a flat surface for mounting a window frame when you already have a flat surface on the original box top and bottom. The unevenness on the angled edges touching the ground is probably less than the ground already has, and it can be nestled in to seal it.

Also, the original box can be built to exactly fit the window frames you have, without calculating the dimensions of the angled cut surface.

Genius!


While I don't believe I get enough sun in early spring to make them worthwhile I will definitely be building cold frames next fall. Hopefully I remember this post!

wayne fajkus wrote:I just read "the  new organic grower's four-season harvest" by Eliot Coleman. It was good and he had a good tip for building coldframes. Build 2 at a time. When you nail a triangle to a straight board you don't get a lid that is level with itself. I"ll draw a pic to clarify.

The basic build is to make a box, then cut at a diagonal on the ends. This turns it into 2 coldframes. The cut side goes down. You have a perfect top on each one for applying the glazing or a lid.

The only downfall is the side walls do not go straight up.

"The only downfall is the side walls do not go straight up."

Sometimes we have to be smarter than the materials that we use.

Turn the frame upright and you have the right angle, straight side walls you desire. ;)  

wayne fajkus wrote:Here is the small problem it corrects. The back wall of the coldframe sits higher than the sidewall that intersects it.

Great way to create 2 cold frames the easy way.
Indeed, Wayne: "sometimes, the answer to a problem is nothing":  When you built the cold frame, everything was flush and all angles square, right? Having slanted walls would not bother me in the least: Lay both frames so that the straight side is on top. Ask yourself: In which way is having slanted front and back walls a problem? It *creates* a problem if you want all walls vertical, but if you don't, you just have to install the lid, and you are done.
This way, the lid will also lay flush and flat square on the contraption. Since you orient the cold frame so it looks South, having the tall North wall slanted Southwards it will still admit just as much sun. The *South* wall will actually invite a little *more* sunshine in. In the 4th picture from the top, flip the one on the left: You will get 2 cold frames with slanted walls but flush tops, so there won't be the discrepancy you noted. It may also make attaching the top hinge easier since you have a right angle at the top [between the tall wall and the sides]. Keep thinking outside of the box, and Good luck!

Here's a pic. The closest one is from this thread. You can see the sloped back wall compared to the one next to it. Building them in pairs (like this) has the advantage of absolutely no scraps left over.

wayne fajkus wrote:Here's a pic. The closest one is from this thread. You can see the sloped back wall compared to the one next to it. Building them in pairs (like this) has the advantage of absolutely no scraps left over.

I really like the roof on the close one: I think it will shed water and snow much better. And see, there is nothing wrong with having slanted walls in front and back. Well done!, Kudos! Hats off to you! I love this way of building two cold frames as indeed, nothing is wasted.

I like the looks of those in the second picture better than the first picture. Looks like they have much taller front wall which I think is important. What do you use to seal the waves in the polycarbonate?  

The height can be adjusted with either style.  I am not in a heavy freeze area. It might dip below freezing overnight but rarely during the day. I dont put any seal on them. I remember wood strip being sold that were cut in a corrugated pattern. Not sure if they still exist or if the market has gone to only rubber and foam.

Glazing can be anything,  including recycled sliding glass door panels. Thats a good example where the this style works well. Trying to figure out the 30" x 80" lid while making it sloped can cause frustration. Build the box to the size of the door panel or window (s) and you are home free.

You can hinge the whole box or just the glazed lid. Either of those can have a counterbalance weight hanging off the back so its not heavy to open or close.

Mark Reed wrote:I like the looks of those in the second picture better than the first picture. Looks like they have much taller front wall which I think is important. What do you use to seal the waves in the polycarbonate?  

I'm in a cold area, that's  why I liked the lower front wall: I need all the sun I can get in the cold spring. [But that is really my only reason, and the few inches may not make all that much difference]. and yes, I think that sealing the waves in the polycarbonate may be more important, in the end than the height of the front wall.
.

It gets pretty chilly in my area too ad I use my frames not only to start spring transplants but to grow cold tolerant like lettuce and such in the winter. My frames are considerably taller and the front, always south facing is also transparent. Mine are build of junk store obtained aluminum storm doors and that similar polycarbonate which I've sealed with synthetic pillow stuffing mixed with silicone caulk. Kind of miniature like greenhouses or greenhouse/cold frame hybrid.  I actually scored some large pieces of flat acrylic that was being thrown away from a remodel,  it's nice and flat so I have one made with it and enough to make two more.

The inside of the back wall in mine is insulated with old black carpet.  I kind of like that slanted effect to those pictured, I'm thinking that might be lined with a reflective material instead of black to maybe help increase light exposure during our frequent spells of long dreary weather.  

Mark, same with me. Here's a lettuce picture I took yesterday.  Its a restaurant stainless trough, like a salad bar might use. I built a clear lid for it. Its elevated and has a drain spigot. I keep a bucket under the spigot to catch the nutrient rich water that drains out.