new 4 x ? arch build

[tcross]

i have a buddy with a bunch of free 1/4" angle iron who happens to be a decent welder so I have decided to forgo the block arch and have him weld me up a 4x something arch! i'll probably make it 4x6 as I have a 4x4 syrup pan that will be used this year (I'll cap the 2' and make a makeshift pre heater out of copper coil then modify the fire box next year) and next year i'll get a 2x4 for finishing! I have access to a bunch of FREE aluminum sheets! the kind that is used to sheath job trailers with. So my question is... if I use 2" of fiber board or blanket and then put full bricks over it... or at least the fire box section... will the aluminum hold up if I rivet/bolt it on? if it will, then my cost savings will be a decent amount vs. buying plate steel to weld... which probably wouldn't be too expensive?! if the aluminum would only hold up for a short time, then I would go the other route or use it for this year since it's free and when I reconfigure the arch next year, take it off and use steel?! anyone have experience with aluminum for arch sheathing? any thoughts? would I be wasting my time?

[Kacey small scale maple]

I'm building a 2x6arch right now and if you look on the thread I started before yours a guy said he used aluminum sheeting and it worked fine he has more detail of insulation there
Kacey

[tcross]

Thanks Kacey! I did see that one, but that's the only one I've managed to come across where someone used aluminum for arch sheathing! No offense to him, but i'd like to hear a few opinions/experiences/information! the more the better in my opinion!

[Kacey small scale maple]

Yes, that's a good idea in my opinion it would work fine if you insulate well and also as a plus be rust free!! Like you said the more the better
Kacey

[Pibster]

I used 20 gauge steel on my arch. With 1-1/4" fire brick, the steel is warm to the touch when the fire is really humping. Definitely not hot enough to melt aluminum. I do think you would have to insulate the ramp as well.