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I can print up some "MOON for Prime Minister" posters! :)

On the subject of brand names, why do we still insist on the name Kaowool? Thermal Ceramics have not had a blanket product with a high temperature rating by that name for a long time. It is cerablanket now. I bet there are plenty of people getting caught with that confusion!

I guess that is why we pay big bucks to the commercial guys. There is a direct tradeoff between the solidness of the surface and the heat it can handle unless you use an expensive extra high heat product in the mix, at that point it is no longer a cheap wash. To put it in perspective a lot of potters refused to use this wash because bauxite has been expensive in the past compared to the price of kiln furniture and fuel. I used to run my mum's kiln for her and I think it took me 10-12 attempts (re-coating about 100 shelves all up) to get all the kinks out of this simple wash. It might be simple but still handles a lot of heat, direct flame not so much. Making a little batch and increasing the flux % will lower the initial melting point, that can be good for patching out the lower temp areas on the first layer (around doors and such) and getting a hard layer. Once that is down and stuck, a second layer of wash with less flux in it can be put over the top. And perhaps a band of the top shelf Zirconium stuff in the really high heat working area. That's just opinion, there is big difference between a gas forge and a kiln and I am no gas forge expert. Too much flux and the crystals stick as a clump then they adsorb heat instead of reflecting it. A flux that does not change state or burn away leaves a residue that keeps remelting the wash every time it is heated. (just like dropping some borax on the surface) Thinking about it, I am not even sure that Zirconium crystals would actually melt and bond to anything, they might just be locked in by the surrounding material. Zircopax is indeed a brand name, as is EPK (it is also the benchmark for refractory style clays), as are 95% of the ingredients in a potters recipe. That is the shorthand, it is easier for them to list a brand product and let the reader look it up in a reference and translate that into the specs needed to substitute another product. yahoo

Hi David, I wrote a long tedious boring post about kiln wash when the 4M was having a hissy fit and blocking posts, I thought it had disappeared completely, alas this morning I found a backup copy stuck to some quotes for solar panels and a recipe for chicken laksa. Removing any references to renewable energy and Malay cuisine in an effort to stay on topic, I will attempt it again. Potters have there own shorthand slang that is hard to understand if you are not in the know. I will try and explain the basic principals of Kiln wash for you. A typical shelf coating home recipe will be. 25 grams EPK 25 grams calcined EPK 50 grams Alumina Hydrate 1 grams of perhaps feldspar? If we break it down, EPK is Edgars Plastic Kaolin in other words a kaolin clay that is mined from silt around Edgar in Florida. This clay is basically 1 part aluminium hydroxide 2 parts silicon dioxide and 2 water molecules in the Al2OH3 crystal. The great thing about EPK is that it hold other materials in suspension well and clings to a surface if you dip something in it or paint it on a surface. The problem with EPK is that it shrinks a lot when it is heated to the point that aluminium oxide is formed and the water is released, so it cracks and flakes badly. What potters do to get around this problem, is place a dish of this powdered clay in the kiln when they bisc fire some pottery, this fired clay (calcined EPK) has converted the AL2OH3 to aluminium oxide and therefore does not shrink. Adding this calcined EPK to the mix reduces the shrinkage and eliminates the cracking and flaking. Both the silicon dioxide and the aluminium oxide are refractory materials but aluminium oxide handles higher temperature, so in theory, more is better. This is where the alumina hydrate comes in, it is bauxite, pure aluminium hydroxide (plus some bonded water molecules) So now, in theory if we wash the shelf surfaces and fire the kiln, we end up with a chalky coating that is roughly 70% aluminium oxide and 30% silicon dioxide. The problem now is the fired coating will be very powdery and just rub off as you handle it. The feldspar is added as a flux, so when the kiln wash is fired for the first time, the corners of the crystals that are touching each other will only just melt a tiny bit and fuse together. The end result is a coating that can "only just" be scratched off with you fingernail. This makes it easy to remove melted glaze from the shelves and repair and re-coat the surface but the coating is tough enough to handle daily use and light abuse. The silicates you mentioned are most likely Zirconium silicate (zirconium sand or Zircopax as Frosty has mentioned) added to the mix, obviously this crystal has vastly higher temperature refractory properties than Aluminium Oxide. You will find that most washes and coatings are just a variation on this basic technique. The ingredients may be different to combat oxidising gases, salt, wood gasses or alkaline glazes but what they are trying to achieve will be the same. Hope this is helpful. cheers Yahoo

IMO over time any bituminous roof sealant inside the tire will rot the bead. Seeing that it is a good tire with a lot of life in it, I think it would be worth taking it to someone with a heavy duty tire changer to get it cleaned, serviced and re-seated. The only problem is working out what will remove the sealant. orange hand cleaner, acetone, mineral spirits, engine de-greaser or perhaps it will just peel off????

if you are looking to use it as a precision lathe, the bed needs to be in good condition, a lot of old lathes wear the bed close to the head and they struggle to make a parallel cut in harder materials. if you are looking to justify it on saving time and materials in lathe jobs, it needs to have a decent sized spindle bore. The ability to fit 2 inch stock in the bore lets you lathe and part off rather than using a steady and regripping the job, this speeds thing up a lot. However, there are still a lot of things that you can do with a big old (cheap) lathe that I would be reluctant to do with a $20K new one. Building up parts with a metal spray attachment on the oxy torch and grinding come to mind. your imagination is the limit. I have even used the bed of one to bolt down a precision welding jig. they are also great for making bushes in soft metals, hardwood timber and plastics

You have been yarn-bombed! :blink: http://en.wikipedia.org/wiki/Yarn_bombing

It is a good helmet. definitely use X-mode for low amp work in direct sunlight. I would also replace the pair of batteries and clean the battery terminal connections. the specs for these is up to 3000 hours with the "solar assist", that is not much if you weld as much as I do.

check it with a magnet Ausfire, if it is a true high manganese steel 11% or more it should be non magnetic. High manganese steel like a red kelpie, the harder it works the more it loves it. needs heavy impact or it will not work harden.

I make it 0.0144 m3 by 7849.5 kg/m3 113 Kg (249 pounds in old money)

I buy anti seize thread paste for machinery maintenance and you can never get the last of it out of the can, so that ends up as drifting lube. ATM I am using Molykote P-37, despite the name it contains zirconium dioxide rather than MoS2

3 3/4" face width

Brilliant! Now I know what to do with all my old I-beams. Vintage "anvils" That is hilarious. :lol:

I attended my last auction for this season last weekend. A local private museum sold their collection which included an almost complete range of the Blackstone oil engine. From 2HP to 26HP. Really big crowd, potential buyers from all over Australia. These single cylinder motors are known in the trade as a "hit and miss" which was the original cylinder deactivation technology. The motor freewheels on the inertia stored in the flywheel with the valves shut and the injection system closed until the speed drops enough to engage the governor then it fires for one or two compressions and freewheels a bit more. It is a bit like hearing a V8 as a young lad, you never forget the distinctive sound. The little 2HP motor, the baby of the sale was what most of the serious collectors had come to see. It is not completely original with parts salvaged and made, this didn't seem to matter, it still sold for more than 5 times the price of the more common 5HP version.

Hey Andrew, Have you been around for the first two workshops with Des at your place or do you just leave them to it? How is it all going so far? Are you getting plenty of interest in future tuition?

interlloy 4340 specs I notice in the spec sheet there is no need to preheat and hold before coming to forging temp as with heating 1045 (not that anyone I know does that anyway)

The prime reason for the rocket stove style retort is there is a massive jump in efficiency over older more traditional designs both in super low amounts of energy used and the superior quality of the finished charcoal. Some charcoal I have seen is only fit for biochar for the garden. if your design can insulate the chamber, transfer heat from the firebox and draw oxygen to burn the expelled wood gasses as well as a rocket retort, you are on a winner. I have tried several styles and put up with the smoke and wastage but I would not go back to any of them if I had a choice. There is no reason that LPG could not be used as a primary heat source but BBQ burners are going to be a little tricky.

'?do=embed' frameborder='0' data-embedContent>> some light reading!

My next oil burner is going to be based loosely on Ralph Dean's should be some food for thought there.

The little fellas that visit my garden are happy to do some modelling work.

Thanks for the input everyone. I have downloaded a petrogen operators manual and they do stress that damaging the mating surfaces where the two piece nozzle, mixer and petrol needle touch the brass head will ruin the machine. I have found that the premium ULP we get here with a little bit of Stabil added, will not degrade or gum for months or even years in blowtorches and petrol starter motors, I am confident I could uncouple and flush a torch and the hose in less than a minute if I needed and avoid those sort of storage issues. It sounds like most of the cutting problems are with torches run rich and carboning up in the nozzle, they do say that there is some skill needed to get the best out of them. According to the manual ethanol blends are a no no (so no dewatering additive either). I have Oxy propane and a small plasma in the shop and I buy a couple of small acetylene bottles purely for the odd welding job (like cast iron). Taking two or three full sized acetelyne bottles out in the field is a real pain, from rental, safety, complying with transport laws and just maneuvering them around over rough or soft ground, I would rather not deal with it if I dont have to. I'm probably not going to rush out and buy one tomorrow but it has got me thinking anyway. Christmas is only 9 months away :) and Santa loves this sort of stuff!

A half turn over that length is not quite enough to let the tension in the metal even things out, so it really needs to be soft I am guessing you would have got away with it over 6 inches. 30mm holds the heat for quite a while, perhaps you could have gone past half a turn and backed it off, that may have saved it? If you have some left over and some time to spare, I think it would be fun to play with it a bit to see if you could do a half turn one way, then back to straight, half turn the other way or go past to full turn and back it up and see if it is stretched. Just to see what you can do and get a feel for it. perhaps try a long quarter turn. Compared to 25mm you have about 30% more cross section area in 30mm so it is a reasonable step up in heat needed

Relax Thomas, ole "moneybags" Yaggy might be struttin' around with his chest out and his $5 hammer in his hand........but Is he really happy? wish i could buy a $5 hammer :unsure: :(

I have been looking around at my options for a big gas axe, someone told me that they have seen a lot of oxy gasoline torches on their travels in Asia and it might be worth a look as an alternative to acetylene for cutting up large scrap and running on a duplicator. From what I can gather there are three sized torches that cut 0-30mm, 30mm - 100mm and 100-300mm with the appropriate nozzles and a profile cutting torch as well. He had some photos and they looked to be very clean cuts with a narrow cut width and they were also cutting stacked bundles of rod and stacked plate. Has anyone seen these in action or tried one themselves? photo from Bizmuth Engineering

Google "ron sitko parts" for a number, may not get him during the day. he might be able to help you.