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View Full Version : Anyone make a cutter for firebrick?



TheAndroid
05-14-2008, 11:10 PM
All,
I scored a great kiln deal on eBay last summer and the time has come for me to replace some of the bricks. The bricks have a t-slot looking channel in them which is used to holding the heating element.
I have several replacement bricks but they are plain. Has anyone made a cutter which would work on masonry? I would appreciate any suggestions on clearance angles and cutter design.

Thanks.

Mike Burdick
05-14-2008, 11:21 PM
A masonry blade works okay in a portable saw if you want to cut it "dry". ...or one can get a masonry blade for an angle grinder.

If you don't want to ruin your saw than get a cheap saw from Harbor Freight or Goodwill.

Paul Alciatore
05-15-2008, 01:08 AM
A mason would use his hammer. Mason's hammers have a regular face on one end and a chisel edge on the other. A few carefully placed blows with the chisel edge and one wack with the regular face and you would be surprised at the accuracy and flatness of the cut. Kind of like cutting glass. About 10 seconds or less.

But it takes some practice. Quite a bit of practice. I couldn't do it, but I have seen them do it time after time with no waste.

JRouche
05-15-2008, 01:35 AM
Ill agree with Mike. The inexpensive diamond blades from a source like HF work great!! And while yer there, buy one of their cheapest angle grinders and use it solely for rock grinding. Dont use yer good angle grinder. the dust will kill the bearings and brushes.. Fire brick is really soft so it will cut like butter with diamond. JR

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=46152

derekm
05-15-2008, 03:58 AM
You want to cut T slots in firebrick? Would it be better to cast your own firebricks with the Tslot in them? As regards blades we a thing in the UK called a wallchaser for cutting shallow grooves in plaster and brick work to lay pipes , wire etc. This has two or more small diamond blades and is probably closer to the size of Diamond blade you are looking for to make a T slot cutter with.

PTSideshow
05-15-2008, 07:04 AM
Contact a ceramic supply and see what they sell em for, since almost all kilns have a slot in them you should be able to pick them up or contact the maker for replacement costs most times. Cheaper than the DIY version at least less messy;)
Junk router or one of those, wall board mini routers. If the brick is the soft fire brick. Use any HSS cutter for the router that will give the size of the slot needed. Use the aforementioned cheap saw with the blades to cut the groove from the outer surface of the brick to the depth of the slot back.
Marble guys have a regular circ saw that has the diamond blades,and use a sponge with water to keep the dust down while cutting. I have an attachment for a saw that feeds water, to the blade while cutting. You do have to have a good saw and cord:eek:
If the brick is the harder version, a baked brick you will need a carbide bit with water to flush the dust away.
On the soft ones you may have to make two or more cuts with a smaller width and height slotting blade. and depending on the number of slots needed a number of the cutters.
If it is only a few bricks or a lot of the bricks. casting them, wouldn't be a bad idea. Less mess just be sure that they are dry thru out the brick by slowly heating them to drive off the moisture. Most places that deal in solid fuel stoves and fireplaces will have of can get the castable refractory or a foundry supply/ blacksmith site.

snowman
05-15-2008, 07:26 AM
You use a table saw with any old blade. Angle the blade. Three passes....maybe even two if you are lucky. You break out the excess with a screwdriver.

Wear a respirator, not a mask, but a respirator.

You likely want to replace them with K23 insulating firebrick.

You can also use a router, but I find it more difficult, and the angled slot holds the element just fine. You will have to replace the heating elements, they do not come out in one piece. To do this, heat the elements up to red hot, disconnect and work quickly. Otherwise they stick to the side of the kiln.

If you just have a couple bad spots, it's NOT worth the aggrivation. While kiln building and repair is not precision metalwork, it's a lot more messy.

If you have an industrial boiler repair place local, call them and ask them if they sell K23 IFB, that's where I get mine and they are A LOT cheaper than any ceramics supply house or kiln repair place.

For your replacement elements, contact Euclid's Elements. They are the cheapest BY FAR.

www.euclids.com

kf2qd
05-15-2008, 09:32 AM
Depending on how much you need to repair - you might check out fireclay mortar. I have done repairs on the fireclay inside a boiler with some. you can get dry or premixed. Works great for repairs and patches. You need to let it dry before use and heat the unit slowly the first time.

Frank Ford
05-15-2008, 10:57 AM
These are soft insulating bricks, yes?

I use simple woodworking tools, which are basically destroyed in the process. Some cheap Chinese saws from the Dollar store work amazingly well.


I haven't tried it, but I bet you could use a hacksaw or keyhole saw to make those "L" or "T" slots.

Last time I had to cut a LOT of insulating bricks, I used up the teeth on a cheap saw, and decided to try making my own, so I ground some seriously huge teeth where the old ones had been, and on the back side of the saw as well:

http://www.frets.com/ForumPix/bricksaw01.jpg


I heated groups of the teeth bright orange/red and quenched them with an ice cube as I moved down the length of the saw blade:

http://www.frets.com/ForumPix/bricksaw02.jpg



Crude? You bet, but it worked better than you might have guessed and I made lots of cuts.

Duffy
05-15-2008, 11:51 AM
I did exactly as you want to do. I was given a small kiln that had literally "fallen off the back of a truck." The dealer got an insurance adjustment and one of the employees gave me the kiln. For $11.00, including taxes. I bought two soft bricks exactly like the originals. I put a 7 1/2" carbide "throwaway" blade in my table saw. Firsy I plowed out a groove wide enough and deep enough for the element, then I tilted the blade to cut the channel the element rests in. The whole process took only a few minutes and worked a treat. I DID use a pretty cheap "hobby-type" saw made of plastic and aluminum, but with no alternative I would have used my cabinet saw. The grit is not that abrasive and the bearings are sealed to keep out sawdust.

chipmaker2
05-15-2008, 11:13 PM
You can cut the brick with a carbide coated wire that is made to go into your hacksaw frame. Those blades also cut ceramic tiles very well and is quite handy for cutting odd shapes.
Regards

torker
05-16-2008, 12:04 AM
Or we could just build you one of these..
http://img.photobucket.com/albums/v210/torker/DSC00001-35.jpg
:D

Swarf&Sparks
05-16-2008, 06:30 AM
On that soft a firebrick, just use a coarse hacksaw blade.
I gather you don't have too many to cut?

TheAndroid
05-16-2008, 11:20 AM
Thanks everyone for the suggestions!

I have 10 or 12 bricks to cut. I have a wet tile saw, I just hadn't thought of tilting the blade to handle the element channel. Sometimes my brain obscures the obvious answer in favor of a "cooler" solution.

Alistair Hosie
05-16-2008, 02:31 PM
Well done Frank looking good.Alistair