Neill's spark arrester

[nissanneill]

Having talked about building a spark arrester for my Pompeii, the final result is now in place but not sure how well it works as I have never seen any sparks coming from the chimney in all the firings done.
I only have a small fie today, just cooking 2 batched of bread/bubs and the family roast afterwoods.
Construction:
I cut 3 rectangular holes 180mm long in the top of the 8" galvanised flue, lined the holes with relatively fine expanded metal mesh (that which is sold and used for open fire screens), cut a 400mm diameter disc and then cut out a 50mm wedge forming the conical top. I welded a 30mm ring of stainless steel on the underside to fit the inside of the flue, assembled and fitted it to the oven.
At least if I have a roaring fire, all effort has been done to minimise the risk of sparks coming from the oven.

Neill

[n2iko]

Handsome work there Neill. Are those rivets holding the mesh? (spell-check!)

[nissanneill]

Hi n2iko,
yes there are some pop rivets holding the mesh tight within the flue.
I tried with just plain 3/16" rivets but were not holding the mesh properly so decided to put thin strips of stainless behind the rivets to hold them securely, hence the unused holes in one picture.
I plan on wiring some newspaper up at the top of the next firing just to check the efficiency of the device. I can't really see the need for it but it was inexpensive, easy to make and at least any authority (maybe when the council come to inspect the new pergola) can see that the jobs get done properly.

Neil

[El Puaco]

Pretty classy looking. Do you build to spec and ship world-wide? Seriously, that is some nice work there.

[nissanneill]

Hey,
in all seriousness, that only took an hour to make and cost around Aus$25-30.
It is a very easy thing to do and required only a small angle grinder with a 1mm cutting disk, a drill and some pop rivets. I welded the cap together but could have used rivets instead.
I really rushed it and could have/should have done a better job, but who is going to be critical of it 15' up in the air??

Neill

[Bacterium]

looks good Neill.......I just need to find some stainless mesh and do mine

[nissanneill]

Hi Damon,There is a wide range of products available , varying in price and minimal size orders. I purchased an offcut, although not stainless, it was there and for small change.
Contact:
Locker Group,
U8 5 Drury Tce.
Clovelly Park
SA5042
Ph 8276 4745 and view at:
Locker Group - Expanded, Perforated & Wire Products
I dealt with a very helpful lad Matthew Brandon-Brown.
I have an offcut from mine, 520 x 300mm expanded aluminium that you are welcome to if you wish.

Neill

[Bacterium]

thanks for the offer Neill....I'm trying to keep as much of it stainless to get maximum life out of it. I've even used stainless pop rivets.

[david s]

I think it is better to use stainless self tappers. That way you can easily remove the cowl for maintenance. Drilling out a stainless pop rivet is a pain.

[Bacterium]

Hi David,
thats a good point......if I ever have to take the top hat off I think I will change over to self tappers.......after I have cursed at drilling them out

Fortunately I have a 2 piece flue, which has a tapered join in the middle. I've set it up so that I can easily pull the top half down for cleaning (mainly the inside) yet it has stood the test of high winds and rain.

......having had experience with fixing various fan extraction equipment on roofs(and various other electrical stuff in industrial environments).......I can highly recommend stainless for longevity.