For each turn-in of this quest you receive 25 reputation with the Thorium Brotherhood (when neutral - not sure if this changes after you hit friendly).

(Human Alliance 0-3000 reputation)
After done Fiery Flux quest, you get 275 rep. That is 2725 rep to go.

To save more heavy leathers, do 3 another quests from board near Lookout Captain Lolo Longstriker.
And 3 quests too from Hansel Heavyhands.

Each gives you 275 rep = 1650 rep (alliance human). That saves around 60 turnins = 60x4 = 240 iron bars or 240 Kingbloods (or 60x10 = 600 heavy leathers). There is now only 1075 rep = 39 turnins = roughly 160 pieces for iron bar or kingblood (390 pieces for heavy leather).

Yes, you need only 160 / 390 pieces for 3000 rep instead of 400 pieces!
That saves grinding time and money very much! If you don't want 6 quests, you're pretty crazy doing.

These are 6 quests you can do easy around the Cauldron.

And Blacksmithers can do extra rep with Imperial Plate gear.
Look at the list http://classicdb.ch/?faction=59#quests

This was copied from another person's post but it appears to be accurate.

OK - here is the lowdown ... It aint my brain but itz fresh...
If U need to cozy up to the Bros then here is the means by which U can do it. See Master Smith Burninate in Searing Gorge

Neutral --> Friendly = 3000 rep
Friendly --> Honored = 6000 rep
Honored --> Revered = 12000 rep
Revered --> Exalted = 21000 rep

Neutral --> Friendly
* turn in: 4x Kingsblood, 2x Incendosaur Scale, 1x Coal
= 25 rep (27.5 for humans) each turn in
= 480x Kingsblood,
= 240x Incendosaur Scale,
= 120x Coal (-10% for humans)

* turn in:
10x Heavy Leather, 2x Incendosaur Scale, 1x Coal
= 25 rep (27.5 for humans) each turn in
= 1200x Heavy Leather,
= 240x Incendosaur Scale,
= 120x Coal (-10% for humans)

* turn in: 4x Iron Bar, 2x Incendosaur Scale, 1x Coal
= 25 rep (27.5 for humans) each turn in
= 480x Iron Bar,
= 240x Incendosaur Scale,
= 120x Coal (-10% for humans)

Friendly --> Honored
* turn in: 4x Dark Iron Residue
= 25 rep (27.5 for humans) each turn in
= 960x Dark Iron Residue (-10% for humans)

Honored --> Revered
* turn in: 10x Dark Iron Ore
= 50 rep (55 rep for humans) each turn in
= 2400 Dark Iron Ore (-10% for humans)

* turn in:
2x Core Leather
= 150 rep (165 rep for humans) each turn in
= 160 Core Leather (-10% for humans)

* turn in:
1x Fiery Core or
1x Lava Core or 1x Blood of the Mountain
= 200 rep (220 for humans) each turn in
= 60 cores/botm (-10% for humans)

Revered --> Exalted
same as above except:

4200 Dark Iron Ore (-10% for humans)
280 Heavy Leather, (-10% for humans)
105 cores/botm (-10% for humans)

Edited, Jan 13th 2007 6:08pm by Raxcks

This is good for a hunter. Most creatures in The Badlands drop Heavy leather 100% with skinning.
Just like the scales will drop 100% from the incendosaurs.
Be honoured with your own fraction and at least Sergeant and the coals will only cost 4 silver.
Its now not to hard to become friendly with the Thorium Brotherhood. Just deliver 1600 heavy leather. Piece of cake :D

Edited, Sat Oct 8 13:36:04 2005

For alliance, I've found that the turtles north of Theramore along the east coast of Dustwallow Marsh to be the best. Yes, you do get some junk that you have to vendor but, its not far, no big time loss. Whats nice is the turtles have an 80%+ drop rate on heavy leather and in all my time there I've only saw 2 horde there. I have 4 lvl 60's that did all their lvl 40 mount grinding there. Horde could grind there too but its a much farther and difficult trek to dump the junk.

Edited, Wed Dec 14 20:47:19 2005

Why is the heavy leather requirement over double the amount of kingsblood you need, which is easier to get in some cases as you can get to it at a lower level so just create an alt

10 heavy leather is a little too much for 25 rep if you compare it to 4 kingsblood or 4 iron bars. They should reduce the number =/