DIY Forge

[ateallthepies]

Started the construction of a small forge today. Went to B&Q and got some Perlite, Fire cement and spotted a metal watering can that would make a good size housing though a bit pricey at £15! I already had the sand and cement and other bits.

Took the the watering can apart and put 4 bolts in as legs. Fitted a small steel pipe for the gas torch inlet and taped up the holes that remained with silver foil tape.

I found a cardboard tube to use as a mould for the cavity and then mixed the mortar and added the same volume of Perlite and made a dryish mix that was put around the tube and tamped down in stages. A final wetter mix capped it off.

Waiting for it to cure now and fire it. I have a pot of Fire cement and May butter the cavity with it but not sure if this will be needed? Will update when fired.

Any observations as to whether this will work gratefully accepted!

 

[Disco1]

Looks good as they say the proof of the pudding is in eating. It should work fine.

 

[ateallthepies]

Hope so? I only used the one bag of Perlite so I have backup if needed!

Anyone know how long it needs to cure before the first firing?

 

[Disco1]

Look forward to seeing it fired up.

 

[peterbermingham]

I would leave it a few days and don't give it much heat to start with you could use this stuff instead of the cement http://shop.vitcas.com/

 

[rorymax]

Now that it is cast, I would suggest submerging the entire forge in a drum of water for as long as 30 days or more, if you can wait that long.
Allowing a decent curing time reaps results.

Check out concrete curing on tinternetwebbbythingy.

 

[David LaFerney]

If you used portland cement as the binder it will erode pretty quick at high temps. If you line it with ceramic wool and coat that with refractory it will help. Also some building sands also break down pretty quick - silica sand (pool filter sand) can tolerate high temps.

Still - it will probably work fine. Nothing lasts forever when you expose it to 1000 C. Nothing which is cheap and easy to get anyway.

Have fun with it though.

 

[ateallthepies]

Too late Peter! Before I saw your post I had already fired it up! I'm not known for my patience was running low on Mapp gas which was probably a good thing but found another blow lamp and let it cook a good 3 hours.

Was still steaming after that gas ran out! No problems as of yet that I can see? Will just have to let it air dry now.

Talking of empty gas cans, any suggestions on what to make with the Mapp gas cylinders appreciated! Also some advice on if I can connect up a 15kg Butane or Propane Cylinder to my forge and what parts I would need? I have the gas and regulators but would need a torch of some kind?

 

[Dave Budd]

i'm afraid I can see a few flaws with that forge

The cement won't hold up to forging temps, it'll start spalling off very quickly.
The mass of cement will take ages to heat up. This is the same for proper castable refractory too, it is both a benefit and a down side. I doubt the peralite will help a lot
You'll likely need to replace that burner too, i think it will be a bit under powered and certainly expensive to run

Still, it's worth a go and I hope it works ok

as for replacing the burner. If you don't want to get a proper forge/kiln burner such as these http://www.castreekilns.co.uk/bur6---burner-kit-4500-btu-194-p.asp then you could use a large (at least 1") propane blowtorch head. There is a reason that virtually all real gas forges use propane rather than Mapp or Butane

 

[ateallthepies]

Ouch, £90! Gonna have to see if there are any cheaper EBay specials about!

Do you think a coat of proper Fire Cement would help on the inside at all?

 

[Robson Valley]

I vote that you run it as is until you wreck it. That's a really good way to figure out what to do next.
Size, shape, materials, operation cost. ... In the meantime, I hope you get a blade or three out of it.

 

[ateallthepies]

Hope so, nothing ventured and all that.... Will only be an occasional hobby forge.

 

[Dave Budd]

there is a lithuanian chap who sells forges and burners on Ebay. They are much cheaper and very good by all accounts. Most of the forges that I have seen that use improvised refractory materials are quite frankly a waste of time (and materials, and fuel, and of course money!)

 

[ateallthepies]

Hmmmmn, not sounding too good.

Was hoping something something cheap and maybe cheerful like this ..... http://www.ebay.co.uk/itm/Gas-Torch...977?pt=LH_DefaultDomain_3&hash=item20ef280989 ....would do?

I'm only about £20 in so far on this project so if it's a disaster not much lost!

 

[Disco1]

http://www.ebay.co.uk/itm/New-DFS-1-Bnr-LP-gas-Forge-Knifemaking-Welding-Blacksmith-/251333082716?pt=LH_DefaultDomain_0&hash=item3a849e7e5c

I know its still £140.

 

[petrochemicals]

Still - it will probably work fine. Nothing lasts forever when you expose it to 1000 C. Nothing which is cheap and easy to get anyway.
.

http://screwfix.com/p/no-nonsense-fire-cement-2kg/50751

There must be a heating engineer on here!

 

[Dave Budd]

that screwfix fire cement is ok for little patches and plugginholes, but it really isn't up to being heated constantly. I have used it in the base of my coke forge to plug hols in the past and it normally lasts less than a day before it pops out in little pieces.

The burner in the link will probably do at a pinch if you have it in a small chamber and you use propane rather than butane. Maybe a chamber of no more than 4x8" and you might be in luck. I have used a cheapy (silverline?) torch like than with a half inch tip on it to run a small forge for drawing tangs out. I think the internal dimension of that was only 3x5" and I used proper refractory blanket since I have it lying around anyway.

The forge linked to is the Lithuanian chap I mentioned. A young friend of mine bought his cheapest forge and has managed to make a piece of damascus successfully in it, so it has the heat needed Note though that his regulators don't fit UK cylinders, so you'll need to get one of those (but he does knock some money off the list price normally due to that)

 

[David LaFerney]

There are materials you can use to make a forge besides the mainstream ones that you can order from refractory and blacksmith suppliers - sodium silicate for binder, pearlite insulation, silica sand aggregate, etc... But the reason smiths (usually) use expensive ceramic wool, satanite, and refractory bricks instead is that all considered the substitutes are more expensive because they don't last.

If you want a good cheap hobby forge just google "2 brick forge." If you want to pattern weld swords then you may as well get out the wallet.

Or go old school and build a ground forge - which might make a pretty cool demonstration at a meetup. Especially if you used a big manual leather bellows and grew out a good beard.

 

[David LaFerney]

http://screwfix.com/p/no-nonsense-fire-cement-2kg/50751

There must be a heating engineer on here!

If there is, it isn't me - I'm just a guy who wasted money and effort trying to build an economical (AKA cheap) forge using alternative materials. I think the saying is "Penny wise, but Pound foolish."

 

[mrcharly]

I had one go at forging

dug a hole in the garden on a bit that is a bank. About size of a 20l drum. Filled it with wood, got fire burning and sealed it off. 36hrs later opened it up, fair bit of charcoal, some unburnt wood.
dug a hole into the base of original hole, shove a bit of pipe in it and connected that up to vacuum cleaner on blow.

Lit charcoal. place bit of steel on glowing charcoal. How hot is it getting? Whoops the steel just melted . . .

Tried again with someone turning vacuum cleaner on/off to keep things a bit under control - that worked.

Twas a lot of work but fun.