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[binfordw]

Been lurking again, as its about time to get rolling on my project.  I picked up some extra steel a few days ago, and gave the local shop I do some jobs for a drawing for bending my firebox up.  Once I get that back, I'll be able to start things!


I've decided to keep a running tally of the parts+expenses as best I can, I'll update as I go.

1. Firebox fab work (bending)-  3/16" steel +labor                  $190
2. 4x10' 3/16" sheet                                                                $180
3.  5x5'  1/4"  sheet    (free(!), but I'll add the current cost     $160
4.  Tubing --   20' x 3" 14ga,  80' x 2" 14ga                             $200

Running total                                                                          $730                                                                         



A few pictures I had onhand of the drawing I have started.

[slimjim]

How are you going to close off your bypass? I have some take off doors from our scrapped boilers with nice latches if you are interested.

[binfordw]

Well,  the drawings aren't finalized to the smaller details.  The bypass will be level with the bottom of the access chamber, and have a lid that is lifted via linkage from the front. 

I appreciate the offer for the doors-  I plan on just making my own.  Not 100% sure how yet, but I figure if the doors I make do warp after a bit of time, I'll just redo them differently.

[binfordw]

Picked up the firebox halves today, and had a bit of time to cut the back panel of the firebox and weld it in.  The bent halves didn't quite fit the drawing, but it was close enough.  Still better than welding all those seams!  Everything else should match up well as its all cut from the drawing.

[binfordw]

Had a bit of time this morning after work to make progress, pretty excited to make this thing look like a boiler.

My firebox is 48" long, so per my drawing I needed 60" for the secondary- to allow room for the heat exchanger tubes.  I settled for a 57" long secondary, as it was what I could fit on the table.  I had some 5x5' .25" handy, so I plasmacut my secondary from that.  I had briefly considered having the local shop bend the secondary, but I already had the steel, and my labor is cheap!  I cut the panel with .375" tabs about every 2 feet on the bend lines, that way all I have to do is fold it like paper (heavy paper!), square it and weld.


Looks like I can pick up some tubing soon for the heat exchangers.

[binfordw]

Finished welding the secondary seams, and cut and added the front panel this morning.

[binfordw]

Well my tubing was in this morning, so I cut the 3" into lengths and tacked onto the mount plate.  Tubing is about 14ga, and looks about spot on as to what I wanted.  Thick enough, but not too thick.  Should be plenty of heat transfer- especially if I slip turbulator strips in later.  The 2" I got for the 2nd/3rd passes is 14ga as well.

I've got the rest of the week off from work, so hopefully I can get most of the firebox/heat exchangers finished atleast.

[vpd66]

Looks good! How are you going to weld the tubes in and weld the bottom plate to the secondary chamber? Doesn't look like enough room between the tubes to weld around them. How do you plan on leak testing this when it is all welded up?

[binfordw]

I'll weld the tubes to the plate from the bottom side, then weld the plate to the secondary.  The plates just sitting on the secondary for the photo.

As for leak testing, not sure yet.  It might require making some panels/gaskets to cover the door openings temporarily.  I don't expect much trouble, the steel is all new/clean and welds nice.  If theres a leak it will be a spot I forgot to weld, so I'll need to just pay extra attention.

If I can think up a way to use flanges to mount the doors, then I could easily bolt block off plates/gaskets on the openings to test.  Thats probably my best bet.

[vpd66]

I'll weld the tubes to the plate from the bottom side, then weld the plate to the secondary.  The plates just sitting on the secondary for the photo.

As for leak testing, not sure yet.  It might require making some panels/gaskets to cover the door openings temporarily.  I don't expect much trouble, the steel is all new/clean and welds nice.  If theres a leak it will be a spot I forgot to weld, so I'll need to just pay extra attention.

If I can think up a way to use flanges to mount the doors, then I could easily bolt block off plates/gaskets on the openings to test.  Thats probably my best bet.

There is a spray on dye with a developer that we use at work to check welds. It works good. Don't know what it costs, but I'm sure if you talked to your local welding supply store they might carry it. Welding something to be water tight is not has easy has people think. Stops,starts,and undercut are some of the places you get pin holes.

[binfordw]

Cut the bottom of the 2nd/3rd pass access box, and started welding the first pass tubes in.





I understand its not easy, I spent a number of years at a previous job where we repaired alot of large hydraulic pipes, as the large die casting presses shook/shimmied and were jolted with very high pressures.  Currently, the business I work for has a large number of sintering furnaces, with water jacket sections we replace here and there.  Also welded various fluid and air tanks over the years in my home shop and at work. 

[binfordw]

Finished welding the first pass tubes in, and cut the back of the access box for the 2nd/3rd pass tubes. Probably cut the front access box next so I can get the tubes cut and installed.

[Sloppy_Snood]

This really looks like a nice unit in the making.  Great welding and design attention. 

[binfordw]

This really looks like a nice unit in the making.  Great welding and design attention. 

Thanks, I hope so!

Im not so sure about the great design attention, I definitely could have done better- always lacked in the design department.  I have become better in the past few years, mainly due to increased CAD skills.

[binfordw]

Cut the front access box tube plate, so I could start getting the tubes cut up and off my floor.  Looks like I'll need another 8 feet or so of 2" tubing, the lengths were random instead of 20's, so there was more waste than I figured.

Probably it for tonight, I have other actual work I need to get done for tommorrow.  Taking the family to an amusement park friday, so no work that day!