Bricks For Brazing Hearth

[Brad93]

Do I need these white bricks

Insulating Fire Bricks High Temperature Resistant | Vitcas Shop

Four grades of Vitcas insulation fire bricks ➤ Insulation fire bricks are heat resistant up to 1650 C / 3000 F for the highest grade ➤ Check out offer now!

shop.vitcas.com

or these sandy ones?

Refractory Fire Bricks - Fireproof and Acid Resistant Bricks | VITCAS

Vitcas high-density refractory bricks with high alumina for industrial kilns, furnaces, and forges. Acid-resistant options available. Heat resistant up to 1650°C/ 3000°F

shop.vitcas.com

 

[Barking Mat]

Either or.

 

[brightspark]

if its just for the lining any heat proof fire brick will do. you can pack round your job using grey broken breeze blocks to retain heat if needed

 

[Screwdriver]

White ones will be very soft and the dust can contaminate parts. Refractory would make a stronger base though both will suffer from damage due to flux. I’d go with refractory for the base and some lightweight insulating blocks as backers/heat shield.

 

[8ob]

@Brad93 , there is a guy down your way that sells s/h fire bricks, I bought a pallet off him for about £1 a brick.

 

[brightspark]

i couldn't give em away out of nightstorage heaters

 

[Milkybars]

@Brad93 I have some nightstore heater blocks you can have

 

[julianf]

we have night storage heater bricks in our log burner, as a poor-mans fire brick

theyre way way more durable than the insulating ones, and do insulate to some extent when hot, but, bare in mind they are designed to heat up, whilst the light weight ones are just designed to insulate

if you want to protect a surface from extreme point heat loads (as i do, the inside of our log burner) then the night storage heater bricks are free - you only have to mention it on freecycle or the like, and you will have people offering to deliver them to you.

but if you want to heat an object without the heat being sucked away, theyre maybe not the best.

 

[optima21]

for a hearth you need light weight refractories for reflecting the heat, the storage heater brick are dense refractories that are designed absorbing heat and releasing it slowly. basically the lighter the brick is the better it is at reflecting heat.

 

[BarrieJ]

Used ex night storage bricks in my forge and in a brazing hearth for over thirty years, couldn't fault them.

 

[Screwdriver]

I use night storage bricks for general purpose worktop heating by direct flame. The part(s) will happily soak up the heat of a direct flame no matter what the insulation or reflecting value of the tabletop might be. I think the question of insulation and density is only of concern when you're building a forge or a furnace. Then the dense refractory will take an age to let the forge get up to temperature but it will stay there, the light weight insulating firebrick allow the forge to get up to temperature much more quickly but the temp drops off as soon as you knock off the burner.

I wouldn't use night storage heater panels in a forge, I don't think they are a refractory grade per se and Google tells me they can be a little bit explody. They're fine for use as a coaster in the forge area or like I said, as a backing for the odd brazed joint.

For my forge (kaolin insulated beer barrel) I lined the it with lightweight insulating firebrick and the "floor" of the forge is heavier refractory brick. The only issue I found with the lightweight stuff is that it is incredibly frangible and combined with flux can contaminate the part, typically a knife or blade which ideally I'd like to keep free from dust and dirt.

For a brazing hearth (I have little/no experience of) I don't think it matters too much on the properties of the base material so long as they are flame resistant. They should not get that hot compared to a forge/furnace so really it's just durability which is important. I would imagine though that if you left an oxy/acetylene flame directly on a night storage brick for long, it would burn up quickly and very likely crack or shatter. They are not rated at the 1200/1600C of true refractory material.

 

[zeppelin builder]

brown houshold firebrick ok for brazing
white stuff more for crucible stoves

 

[dan.taylor.1]

PotteryPro-UK - StudWeldPro-UK

Suppliers of Scruffs and Snickers work wear. Punk and Holdon tools. Supplies to build your own pizza ovens and fire pits.

swpuk.com

I used these guys for my forge bricks, they were incredibly helpful and the lass I dealt with scoured the warehouse for some odd sized ones I wanted.

 

[jim noonan]

I built a large pizza oven from storage heater blocks which I quartered using a stihl saw...a deeply messy process. As others have said they absorb a massive amount of heat so take time to get to temperature but in 10 years they have remained in tact despite the heat cycling and the outdoor conditions. I use two of these as the base for my small forge, the sides and top being insulated with ceramic blanket. I have two substantial propane burners firing it. I have never encountered these blocks decaying from heat but they are a bit friable and subject to damage from physical impact. However the lightweight insulating bricks imo would be better around a small brazing hearth to reduce heat loss. They could be protected from erosion with a thin coat of fire clay and lime mix or a proprietary high temperature zircon type paint coating. For larger structures where bonding lightweight blocks is needed, the traditional fireclay, lime and fine sand mixes have proved extraordinary over the millenia but you need to be prepared to patch and mend.

Just my experience to date.

Ta

Jim

 

[jim noonan]

With regards to storage heater blocks breaking explosively I think this is highly unlikely as the tensile forces bonding their particles seem quite weak, I can envisage the possibility of cracking but I doubt any significant explosive force is capable of building up and bring suddenly released. We're that a possibility, it seems unlikely that they would be used so widely though others may know more.

 

[James1979]

With regards to storage heater blocks breaking explosively I think this is highly unlikely as the tensile forces bonding their particles seem quite weak, I can envisage the possibility of cracking but I doubt any significant explosive force is capable of building up and bring suddenly released. We're that a possibility, it seems unlikely that they would be used so widely though others may know more.

When I were a kid we had a massive open fire place in a couple of the rooms. My dad and I built a lining of storage heater blocks round the hearth. No bond, just stacked them in dry.

it reduced the fuel needed and they stayed warm overnight like a storage heater. Never had an explosion. The ones against the direct heat never lasted that long but you just scrape them out and replace them.

worked well on the whole.