Thoughts on a wooden built kiln

[deluxestogie]

Here are my current thoughts. Extruded polystyrene rigid foam does not absorb water. At 2", the R value is 10. Below, is a detail of the join of the sides to the back and the front verticals. Since the door is also framed, a hinge (perhaps a piano hinge) that is attached to the vertical wood braces will require that the 2" of insulation at the hinge corner not overlap at all. Maybe a flexible sheeting over that area can solve the problem. I think the foam sheet on the bottom of the kiln can be simply screwed on through some plastic or rubber floor protectors, or maybe casters.

As suggested above, any screws passing from the exterior, through the foam would be supported with a thin wood slat.

2" Extruded Polystyrene (XPS) Rigid Foam Insulation: http://www.homedepot.com/p/Owens-Co...-Sheathing-45W/100320352?N=5yc1vZbaxxZ1z0z6k1

Foamboard Adhesive: http://www.homedepot.com/p/Loctite-PL300-10-fl-oz-Foamboard-VOC-Adhesive-1421941/202020476

This concept allows for disassembly. Foil tape over the exterior foam joints could be easily removed for separating the panels for storage.

Since the XPS sheets weight about 7.5 pounds each, the completed kiln should come in well under 30 pounds.

Bob

 

[deluxestogie]

STYROFOAM extruded polystyrene products will melt when brought into direct
contact with high temperature heat sources. The maximum recommended
continuous operating temperature is 75°C.

http://msdssearch.dow.com/Published...foam/pdfs/noreg/716-00150.pdf&fromPage=GetDoc

So, the max "continuous operating temperature" is 167ºF. It might be usable for flue-curing, if the max temp is kept below 165ºF.

Bob

 

[Brown Thumb]

Looking like you are figuring it out.
They make a special screw with a big round plastic washer on it to hold foam board down tight Also, I used them on my roof when I put 4 in. Foam down.

 

[leverhead]

So, the max "continuous operating temperature" is 167ºF. It might be usable for flue-curing, if the max temp is kept below 165ºF.

Bob

LOL, that's cutting it pretty close! You might consider some kind of protective shell on the outside, even cardboard handles more abuse than foam board.

 

[Brown Thumb]

I would think they have at least a 10% safety margin built into that figure for people who like to push a products limits.

 

[deluxestogie]

You might consider some kind of protective shell on the outside, even cardboard handles more abuse than foam board.

You might be right, but this pricey board is apparently fairly sturdy.

Easy to work with. Score with a box cutter and snap as you would a piece of sheet rock. It breaks clean without any mess. I used it to insulate a gable wall. It can be hammered into tight areas by placing a board between the foam and the hammer. It's pricey but well made.

Great for carving - the thickness was a bit challenging but it's no issue if you have the right tools. Stands up very well to stress - including falling 30ft off a building

My greatest concern about the temp limit for flue-curing is that it may become deformable. It would certainly need some testing at that upper temp.

Bob

EDIT: How does one transport a 4' x 8' object in a small sedan?

 

[Brown Thumb]

I would think it would remain stable but not live up to the products insulation property's,
You will not melt or deform foam at 170 degrees.

 

[Knucklehead]

EDIT: How does one transport a 4' x 8' object in a small sedan? Bob

Your piece appears to be perforated at strategic 16" or 24" sections. If you're building no bigger than a 4x4 box, then snap the boards in half at the perforations, giving you four 4x4 pieces. Or, if you are building 2' deep, you can snap one 4'x8' piece into four 2'x4' pieces, the other into two 4'x4' sections. What ever loads best. The guys at the supply store can help you do this. They'll even cut plywood in half for you.

 

[deluxestogie]

I considered that. I guess I'll have to crank out some calculus to figure out the optimal size pieces ahead of time. ["My likely dimensions will be ~4' height; ~30" width; 20-24" depth."] My available space assumes these are outside dimensions.

Bob

 

[Knucklehead]

I considered that. I guess I'll have to crank out some calculus to figure out the optimal size pieces ahead of time. ["My likely dimensions will be ~4' height; ~30" width; 20-24" depth."] My available space assumes these are outside dimensions.

Bob

I was talking about how to fit it into your car.

 

[DGBAMA]

So, the max "continuous operating temperature" is 167ºF. It might be usable for flue-curing, if the max temp is kept below 165ºF.

Bob

This is the foam board that I built by flue cure chamber with. No issues, 160deg stem drying.

 

[deluxestogie]

I was talking about how to fit it into your car.

Yes. And if I cut it to convenient sizes for the car, they may not be efficient sizes for the required panels. It's a cookie cutter problem.

This is the foam board that I built by flue cure chamber with. No issues, 160deg stem drying.

Yay!

Bob

 

[ChinaVoodoo]

Looking like you are figuring it out.
They make a special screw with a big round plastic washer on it to hold foam board down tight Also, I used them on my roof when I put 4 in. Foam down.

I did the underside of a floor. There's glue that comes in calking tubes specifically for the rigid foam insulation.

 

[Brown Thumb]

I mentioned the screws, Due he wants to Disassemble it.
But glue on the attaching studs ect. Is a good Idea.

 

[ChinaVoodoo]

I mentioned the screws, Due he wants to Disassemble it.
But glue on the attaching studs ect. Is a good Idea.

Right! I need to pay attention.
The question about the screws is, will they strip the foam after going in and out several times. What about gluing concrete anchors into the foam, and bolting it together?

 

[Knucklehead]

Right! I need to pay attention.
The question about the screws is, will they strip the foam after going in and out several times. What about gluing concrete anchors into the foam, and bolting it together?

The foam will be screwed to wood supports. He plans to back the screw head with thin wooden strips or large plastic washers to spread out the load. The screws will have no holding power in the foam. The foam will just be sandwiched between the wood and the large screw heads or wood strips with a clamping type hold.

 

[DGBAMA]

I will add, the aluminum HVAC tape adheres very well to the foam, and is what I used for sealing.

 

[Jitterbugdude]

I will add, the aluminum HVAC tape adheres very well to the foam, and is what I used for sealing.

I must have had reject Home Depot tape. I used the metal HVAC tape and it pealed off. There is the possibility though that my foam board could have been dirty.

 

[Chicken]

your thinking along with my thought's also....

i believe this .. is gonna be my year of building me '' something '' versitile.. for colour curing and kilning,,

but im just gonna make a big. metal building... it aint gonna look pretty...

it will proablly end up looking like something that fell from the space station and landed in my yard.

 

[ChinaVoodoo]

I will add, the aluminum HVAC tape adheres very well to the foam, and is what I used for sealing.

That glue on that tape gives off a terrible smell over time. I masked off my xray id flasher with some a couple months ago, and the heat from the light bulbs makes it stink.