Patio Reverse Flow Build

All about smokers hot and cold
rustoration
Posts: 18
Joined: Thu Jun 12, 2014 9:49 pm
Location: Adelaide

Re: Patio Reverse Flow Build

Post by rustoration »

So I had some time today to kill waiting for filler and sealant to dry on the laundry renovation, I decided it was hinge and smoker door time.

First step was to get the hinges positioned and welded on which I thought went fairly well.

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Next step was to cut the remainder of the door. I used the same trick of a 4x2 strapped onto the side of the tank as a guide for the bottom edge of the door and then free handed the side cuts.

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All good, or so I thought until I tried to open the door. The middle hinge was binding up preventing the door from opening more than 30 degrees or so, to gety it to open I had to remove the bolt.

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Looking at the mid section of the tank, appears there has been some warpage, either from welding the hinge on or from the earlier repairs. Not sure if i'm going to try to fix this to just cut the hinge off. A decision for another day...

Meanwhile, I pressed on regardless with the door and fitted up some 30x3mm flat bar on the edges of the door to allow a gasket to be fitted up later. Given the potential warpage already and some lessons learned from the interweb, decided I would plug weld the flat bar on to avoid putting too much heat into the door.

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All up, pretty happy with today's progress, which might be it for the weekend now that the laundry looks ready for paint...

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Low n' slow... The art of bbq and classic VW's
Dez
Posts: 66
Joined: Sun Jan 18, 2015 1:52 pm
Location: Adelaide Hills

Re: Patio Reverse Flow Build

Post by Dez »

Looking great Rustoration!
Enjoying watching the build. Plug welds! Wish I thought of that.
That middle hinge. My 2 cents. I'd put my eye in line with the hole and watch it. Hold it at its most out of wack spot. Then jam a die grinder in there.
Dont wanna tell ya how to suck eggs but. You look like ya got it going on.
Cheers.
Dez
rustoration
Posts: 18
Joined: Thu Jun 12, 2014 9:49 pm
Location: Adelaide

Re: Patio Reverse Flow Build

Post by rustoration »

Back on the tools today and figured it was time to get the smoker off the floor.

Started the morning off back on the CAD to get my dimensions right then cut, shaped and welded up some 40 x 40 square tubing on the work bench.

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Tacked it up with the smoker upside down and the original stand cut away.

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Before finishing off the welds from all manner of angles once I had it sitting square and level.

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Certainly learned a few things along the way today, particularly the challenge of welding the thin box section to the heavy plate of the smoker and how to repair blow through holes. Thankfully most of the worst mistakes are on the underside out of view. Just need to attach the 125mm heavy duty wheels sourced from fleabay and the smoker is mobile.

For keen of eye, you may have noticed I've fixed the issue I was having with the alignment of the middle hinge. Dez, I eye balled the alignment of the middle hinge thru the full range of motion but there was no way a die grinder was going to rescue it, but I found that a cut off wheel did so middle hinge has gone to the big scrap bucket in the sky. The two remaining hinges feel like they will do the job.
Low n' slow... The art of bbq and classic VW's
rustoration
Posts: 18
Joined: Thu Jun 12, 2014 9:49 pm
Location: Adelaide

Re: Patio Reverse Flow Build

Post by rustoration »

Didn't think i'd be posting more progress quite so soon, but got home early enough to tackle the fire box. Fairly simple process all told given all the pieces were lazy cut.

After first welding on the fire box door hinges, I tacked up all the sides one by one on the workbench using square clamps and magnets. I've left the bottom plate off for now for ease of access for the fire box rails.

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And then tested the door fit again to make sure I hadn't warped it and everything was square.

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After fully welding all of the edges, everything stayed true and square which let me start to picture a bit more what the end product is going to be.

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Bit of a challenge welding the thick plate, probably at the limit of my welder or technique so a little sketchy in a few places, but nothing a grinder can't fix.
Low n' slow... The art of bbq and classic VW's
urbangriller
Posts: 9453
Joined: Sun Sep 14, 2008 8:46 pm
Location: Perth WA

Re: Patio Reverse Flow Build

Post by urbangriller »

Looking seriously good! 8) 8) 8)
Common Sense is so rare these days it should be a Super Power!
Dez
Posts: 66
Joined: Sun Jan 18, 2015 1:52 pm
Location: Adelaide Hills

Re: Patio Reverse Flow Build

Post by Dez »

Been hanging out to see how this beast is progressing.
Looking great!
rustoration
Posts: 18
Joined: Thu Jun 12, 2014 9:49 pm
Location: Adelaide

Re: Patio Reverse Flow Build

Post by rustoration »

Today has been about progressing the firebox and started with adding a flange onto the firebox door for a gasket. Went down the plug weld route and had to make the flange quite large as the gasket that turned up is wider than I order and planned for.

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Despite my best laid plans, the hinge design for the firebox doesn't allow for a flange all the way round so will have to have a think about that. Maybe the gap isn't really an issue, shouldn't be too much air getting in.

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Next it was on to the air intakes and for this I've gone with my interpretation of an idea I saw elsewhere on the web. It uses a threaded rod insert welded onto the first box, then threaded bar onto a lid with steel bar as a handle for opening / closing.

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They aren't quite finished yet. At final assembly I will add a lump of weld onto the thread and trim them off which will restrict them so they only open about 1.5cm, which by my calc is sufficient to meet the flow requirements per the original air intake calculations.

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And that's the firebox and air management done, 2 larger air intakes low on each side of the firebox to keep the fire going and 2 smaller intakes on the first box door to help draft air into the smoke chamber.
Low n' slow... The art of bbq and classic VW's
GarthFader
Posts: 124
Joined: Mon Feb 03, 2014 4:38 pm

Re: Patio Reverse Flow Build

Post by GarthFader »

rustoration wrote:...Despite my best laid plans, the hinge design for the firebox doesn't allow for a flange all the way round so will have to have a think about that. Maybe the gap isn't really an issue, shouldn't be too much air getting in.
Why not have the flange on the inside of the fire box all the way around, rather than trying to have it on the outside of the door?

Love the air-flow controls too... very nice.
Dez
Posts: 66
Joined: Sun Jan 18, 2015 1:52 pm
Location: Adelaide Hills

Re: Patio Reverse Flow Build

Post by Dez »

Any progress on this beast?
rustoration
Posts: 18
Joined: Thu Jun 12, 2014 9:49 pm
Location: Adelaide

Re: Patio Reverse Flow Build

Post by rustoration »

I knew it had been a while since I posted, but didn't quite realise it had been over two months. I guess that's what happens when you have too many house projects on the go as well...

Ah well, the time hasn't been entirely wasted, it gave me a chance to mull over the firebox door latching arrangement and the hinge that I wasn't the happiest about along with the rest of the items I needed to complete my build. This all ended up with a file going off to the laser cutter and some more parts to be getting on with.

The first job tackled was making up a fire grate and box which was made up with some expanded mesh and angle iron. It slides on a couple of angles welded inside the fire box. In the same photo you'll also see I capped off the air intakes with a washer and lump of weld to stop them coming out too far and also ground smooth the external welds to tidy it up a bit.

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After that it was off with the original hinges and on with the MKII version which now totally span the flange (after filling up the gap). GarthFadar, I did think about an internal flange but then that would be different to the smoker door and that just doesn't compute....

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Finally, cracked on with tacking up my door latching mechanism which is very easy to argue is overkill but what the hey.

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I'll finish up the latch mechanism with a handle that sits out from the vertical bar far enough to stay coolish I hope and there is enough free play between the door and box to fit a nomex gasket.

That's it for now, hopefully it won't be so long until I get back to it again.
Low n' slow... The art of bbq and classic VW's
Dez
Posts: 66
Joined: Sun Jan 18, 2015 1:52 pm
Location: Adelaide Hills

Re: Patio Reverse Flow Build

Post by Dez »

Excellent. Glad your still at it. Looking good!
Groovy Gorilla
Posts: 371
Joined: Fri Nov 07, 2014 11:56 am

Re: Patio Reverse Flow Build

Post by Groovy Gorilla »

Looking excellent makes me wish I could weld
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chilling while grilling
rustoration
Posts: 18
Joined: Thu Jun 12, 2014 9:49 pm
Location: Adelaide

Re: Patio Reverse Flow Build

Post by rustoration »

Back on tools this weekend and really starting to see a smoker emerge.

After finishing up the firebox (final welds to the latch mechanism and welding in the bottom plate), cut the smoker chamber, aligned the firebox and welded it into place. Didn't take any photos of these steps but after welding on some brackets and bolting on some wheels have something that resembles a mobile smoker.

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I got a nice series of welds externally but had to plug some gaps on the inside which didn't come out too tidy but these will be hidden when it's all done. One hint I took from the US forums was to leave a small lip at the bottom of the half moon run out which should prevent any condensation, water, fat, etc, running into the firebox. I'll be adding a drain valve before the final weld up as well.

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Last achievement for the weekend was to get the baffle plate ready to be welded in which actually went like a dream. I was concerned I wasn't going to get it in in one piece but thankfully it just squeezes thru the opening and into place.

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I had seen numerous variations of baffle plates, many angled to assist with draining water/fat, etc, but I questioned how many times will I be cooking on a dead level surface that the drain would work as designed? Not many i figured so nixed any fancy design and a flat plate it is. I've made allowances for another drain valve and I will add an upstand at the end of the plate when I weld it in so that i can use it as a water pan or to help when cleaning it out.

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See y'all next time...
Low n' slow... The art of bbq and classic VW's
urbangriller
Posts: 9453
Joined: Sun Sep 14, 2008 8:46 pm
Location: Perth WA

Re: Patio Reverse Flow Build

Post by urbangriller »

This Build is starting to look real good.....I'm looking at my tank in a whole new light!
Common Sense is so rare these days it should be a Super Power!
GarthFader
Posts: 124
Joined: Mon Feb 03, 2014 4:38 pm

Re: Patio Reverse Flow Build

Post by GarthFader »

That firebox latching mech is amazing... Such an impressive build!
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