How much pan sits on the rails

[Paperman]

Never seen a commercial arch so I dont know how much pan overlaps the rails. Built my rails out of 2x2 tube so I can use it to push air over the fire later if I wanted. I have the pan overlap the rail by 1/2-3/8 on each side. Also what is in the center of an arch where the pan meet? My plan was just a piece of flat stock so I can lay a gasket on it. Anybody see an issue with that. Pics to follow.

[whalems]

I don't have any thing between the pans. I think the heat would warp/destort any flat steel crossing over the fire box area. I just put ceramic blanket between the front and back pan. Hope that helps, Mike

[Paperman]

Sounds good to me. So lay a piece between them and push together.

[red maples]

Going by memory never really measured but I think mine is about 3/4 to 1 inch. from cleaning or vibration from boiling they can move a little back and forth not much maybe a 1/8 to 1/4 of an inch but I don't have rail gaskets either not needed. and no gasket or anything between the pans too hot there it would just warp. its not needed.

[RileySugarbush]

That is exactly right. Just keeps strip of gasket between them.

Most rails are made of angle steel as opposed to your tubing. I think many are 2x2 or 1.5x1.5. I made mine out of 1.25x1.25x0.125 which is lighter than most but has been rock solid for four years.

The outside leg of the angle is flush with the pan walls.

One concern with the larger tubing you used is bowing caused by differential expansion. The inside wall will be much hotter than the putter, resulting I the rail bowing inF. Blowing air through them will help.

[whalems]

Sounds good to me. So lay a piece between them and push together.

thats what I did and worked great. and I put ceramic blanket/gasket on the rails to keep the heat on the bottom of the pans. Good luck, Mike

[wiam]

Never seen a commercial arch so I dont know how much pan overlaps the rails. Built my rails out of 2x2 tube so I can use it to push air over the fire later if I wanted. I have the pan overlap the rail by 1/2-3/8 on each side. Also what is in the center of an arch where the pan meet? My plan was just a piece of flat stock so I can lay a gasket on it. Anybody see an issue with that. Pics to follow.

I would be concerned with the tubing without using AOF. I installed AOF last year. It did not work on my rig. After I stopped using the AOF the nozzles eroded away and the tubing warped. The galvanize also burned off the outside of the arch by my tubing.

[Paperman]

Hard to think you would make the tube move much. Guess we will see.

[RileySugarbush]

Yes, it's amazing how much it can move!

What happens is the inside edge gets very hot and expands along it's length
while the outside is kept cooler by the outside air. That makes it bow inwards. The effect can be greater if you use a wider material, especially if it is tubing since the air inside prevents the outer wall from getting hot. That is why the 2" tubing is potentially a problem. You may need to insulate the tubing, or add some AOF right away to keep it a bit more balanced.

[Sako]

I used 2x3 with brick under the 3in and did what you are thinking about with the AOF, I will recommend doing it right away the boil is not even close to compare when blower is turned on, lot less wood consumed and sent up the stack.
Did not notice any warping to my unit.

[wiam]

I used 2x3 with brick under the 3in and did what you are thinking about with the AOF, I will recommend doing it right away the boil is not even close to compare when blower is turned on, lot less wood consumed and sent up the stack.
Did not notice any warping to my unit.

I will say again the warp happened with no air going thru the AOF on mine.

[Paperman]

I was planning on air from the getgo but am stuck on a fan. How much air is really needed? I hear its more pressure than volume. Was planning on trying this fan http://www.surpluscenter.com/item.asp?item=16-1436&catname=electric but dont know if it fits the bill. It is a radial at 3000 RPM so it should make a few In. of pressure. What say ye maple board?

[maple flats]

That appears to be the correct type. Would need some more specs to know if the pressure and CFM is right. Do you have the written instructions I posted long ago to go by? If yes, try to compare that blower with the one suggested for your size arch. If the numbers are close it should work. The pressure seems to be more important than the CFM, but you do need to be close to the right CFM. The biggest reason AOF works so well is the turbulance it creates in the firebox, without it the thing will not work to it's potential.
If the specs compare you have a good find, that price is right. I have used that source to buy several items in the past, from 4.5G generator gas tanks to use on my vac pumps ($18.99 each) to a new loader valve for my tractor with joystick control and power beyond for slightly less than the price to have my local farm equipment dealer rebuild the old one, with no joy stick control and no power beyond.

[Paperman]

Dotn have any more specs. Says 120 CFM but dont know at what pressure. The thing is small I would guess. Simple amp/HP is .209 HP without loss or powerfactor in there. Not alot of juice. Might try one for $30.

[RileySugarbush]

Seems a little weak. I used a half horse and would not go any smaller.

Check out this video on YouTube:

http://www.youtube.com/watch?v=LhiEyMjVx5g&feature=youtube_gdata_player