Pdx 42" update

[JRPizza]

It looks way better than mine did! You are spot on about the accuracy thing, at least from my experience. That is why I didn't use the spread sheet. My ability to set my jig to a few degrees was not good, and even when I set it right I still had gaps. I ended up just using my sliding bevel to eyeball the angle I wanted and transfer to the saw, then did a practice cut to see if there was any Vee left when the bricks butted together. I made any slight adjustments as needed and cut the rest of the course.

[NCMan]

Today's update is a bit of a sidebar as I spent the last day of holiday making a jig instead of cutting bricks as hoped. I hope the pros are patient as my poor carpentry skill and thought might make this update kind of obvious unless you're an amateur like me, in which case hopeful it's insightful and inspiring!

my jig is inspired by @Chipster as shared by NCMan earlier in the thread. I do not have welding tools so worked with wood and prefabricated parts from the hardware store. I got some scrap 3/4 plywood that is used from furniture construction from my brother, who is a carpenter by trade, and also received a gift of some polyurethane finish, which I am applying to improve water resistance for use in the wet saw. I used a piece of angle Iron with 3/8" holes predrilled for the fence, and cut a arched slot with a jigsaw to allow the fence angle to be adjustable. Likewise I put in a long lag bolt with wing nuts and washers that can be adjusted to manage slope.

Because my carpentry skills are total crap, this jig is not square, and not through lack for trying! Fortunately I did get it level. That brings me to my tip for beginners like me - I don't think perfection is required in the construction of this jig. Some people probably can create perfect tools no problem. But there is that risk that things warp or twist during use, or look perfect but are off by a degree. So the advice I have, which comes from my brother, is to measure and adjust the jig settings relative to the saw blade after you clamp the jig to your table. That way, even if you have imperfect tools like me, you can still produce the right finish product! This, of course, needs to be measured on both the vertical and horizontal axis.

Here are some photos prior to application of finish. You may wonder why there is no nut on the pivot bolt and that's because it's a lock nut and I did not want to secure that nut until after the I'm done with the finish. You can also see what I mean about the boards not being square. Sloppy...but whatever. I will just have to be careful to align to the sawblade.

Let us know how it works for you. Best of luck!

[Macrinehart]

Quick question - is the photo below about the amount of sand/fire brick clay needed for under the oven floor, or more? Disregard the existing bricks around the perimeter, they'll be removed. Thanks!

[david s]

Maybe about 1.2cm x floor surface area (in cm2) = volume in cm3 (divide this by 1000 to get litres)

[NCMan]

Quick question - is the photo below about the amount of sand/fire brick clay needed for under the oven floor, or more? Disregard the existing bricks around the perimeter, they'll be removed. Thanks!

Looks good. You need just enough to be able to tap them down, w/a rubber mallet, just a bit, to get them all level and flat. You don't want to use any more than you have to. Also, if it hasn't been mentioned, what I did when first using the brick cutting jig, was to have some cheap soft red bricks to practice on, as I went along. Just a suggestion.

[Macrinehart]

Thanks for the tips. I am using a 1/4" slotted trowel, that's about 1.2 cm.

Before setting the floor I wanted this quick preview of the oven opening. What I've got is a 20" wide opening with 2 ranks of bricks for the landing and a 1.25" offset on the outer rank for the door. Thinking of cutting the cal-sil off at the edge of the front rank, which will leave about 8.5" between the front edge of the heart and the oven landing.

Any final suggestions before I start laying the floor?

Cheers!

[mongota]

One of those "I hate to ask a dumb question" questions, but I'll post it anyway.

Having a full brick length before the door reveal puts your oven door several inches (about a half-brick length) further away from the oven when compared to most builds. Are you planning an insulated door? If so, will the flue be outside of the door?

Your earlier pic of the troweled fireclay reminded me of a japanese zen garden.

[Macrinehart]

Hi Mongo - you know it's funny, I think I have planned things correctly but you're comment has me second guessing myself, even though that positioning is based on the layout I had from my full sized template, reattached below. I could cut off up to 2" on the brick length. The chimney landing is on the outer rank of bricks. I am dispensing with the third rank (which is supposed to be the decorative arch). The chimney landing is outside the door. And the door will be an insulated door fabricated by my blacksmith friend.

[Chach]

Your earlier pic of the troweled fireclay reminded me of a japanese zen garden.

Hahah me too

[UtahBeehiver]

David S actually mentioned the deep entry a few posts back. I deep entry does make if harder to access but your choice.

[Giovanni Rossi]

The perspective of your picture certainly exaggerates the depth of the landing. However, looking at your drawing, the flue is positioned further from the dome than I’ve seen in other builds. Certainly not an expert…just my 2 cents.

[mongota]

It's possible I'm interpreting things incorrectly, but I'll post this and let you and the moderators chime on on this. I marked up your drawing.

I outlined the original location of your TDC brick in YELLOW. As I see it, if you locate it there you'll have to infill a small piece of brick behind the TDC brick, where the LIGHT BLUE cross-hatched area is, if you want to maintain the smooth spherical interior surface of the dome. I have seen builds where builders have left voids back there, but I didn't know if that was your intention.

By moving the TDC brick further back into the dome, outlined by the GREEN line, so the back edge of the brick touches the point shown by the BLUE arrow and BLUE text box, it eliminates the need for that cross-hatched infill piece.

You then cut your TDC brick as shown by the thin BLACK line.

If I buggered this up my apologies, the last thing I want to do is cast doubt in your head about your layout, as I remember myself how confusing it can be!

[JRPizza]

mongota has it right - your arch is a little too far forward. This is what I was trying to explain in post #19 and 20. I should have included the sketch below but I think it is in my build thread too.

[Macrinehart]

mongota - your markup of my drawing clarifies things a lot, thank you!

JRPizza - Iooked back at your post #23, which has the same CAD drawing #133 above. I didn't have all the same context back then, it makes more sense now. I do notice that in your build thread #3 your TDC brick is further forward than the updated drawing, it looks more loke Mongata's markup. From that I assume you advise positioning the opening arch even further inside the oven.

[mongota]

Macrinehart
Mac, you're welcome. I noticed when I blew up the drawing that the drawing I marked up still has your dome opening at 10" tall. I recall you increasing that in previous posts. Still, using the drawing as a generic guide and adjusting the build to your current dimensions should help figuring the in/out range of the TDC brick and thus your arch. Build on!
Best, Mongo