|
Post by pauls on Mar 1, 2017 21:52:01 GMT -5
Cat food tins are good if you can get over the stink of fish when you heat it, the smell seems to keep on coming for ages.
I generally just wipe a small amount of wax onto the dop, just enough to stick the stone.
|
|
|
Post by pauls on Jan 15, 2017 5:54:13 GMT -5
A bit more time for a proper reply to ziggy.
The recipe in that video using plaster and sand for the refractory cement is just stupid. Probably useless after using it once. The same goes for most of the homebrew refractory mixes. At high temperatures things like cement and plaster act as fluxes and help the melting of the rest of the ingredients in your refractory. Aluminium, Lead, Pewter can use some of the better homebrew refractories without failing, for a while. Its much better to spend the money and buy a few bags of commercial pourable refractory, you will save money in the long run.
For copper you must have high temp refractory, a graphite or silicon carbide crucible and a way of getting things really hot. Copper will also require a charcoal blanket over the melt to stop everything oxidising. I did say its tricky.
At "alloyavenue" you will find plenty of ways to make a good workable propane burner, but for the hottest temperatures you probably need an oil burner running on oil obtained at the right price (free)from your local takeaway or auto workshop, Yep thats right you can melt metal with potato fryer oil and sump oil, any old oil will do. The burner is basically a tube through the side of the furnace (Tuyere)with a blast of air from a hair dryer or the back end of a vacuum cleaner. oil is dribbled into this tube and the oil air mixture enters the furnace and burns. There are plenty of fancy designs that preheat things with propane. My furnace is started with a piece of paper and some wood chips and twigs, when they are burning fiercely I turn on the oil, the oil hits the burning twigs, theres a woomph and then it starts roaring, a very satisfying sound. In minutes the inside of the furnace will be white hot. Anyone familiar with combustion knows that your lawnmower wont work if the carby mixture is wrong, too much fuel and you flood it, too little and its too lean and stops, same with the furnace. About a gallon an hour is around about right in mine, more fuel and I need more air and things start getting really loud and hot.
Casting metal is a whole nuther hobby but its potential is really up to your imagination, I have cast backing plates, laps, bearing housings, a part for my faceting amchine, lots more. In aluminium as its relatively easy, I did try copper but struggled to get it melted hot enough to pour, just enough to puddle in a semi melted sludge in the bottom of a expensive crucible and then go solid, of course when you try to heat it up again the metal expands and shatters the crucible. Grr.
|
|
|
Post by pauls on Jan 15, 2017 0:09:06 GMT -5
Ziggy Your husband needs to go to Alloyavenue (http://alloyavenue.com/vb/forum.php). Melting and doing anything useful with copper is quite tricky and requires a fairly sophisticated burner and well built furnace to get to the required temperatures.
|
|
|
Post by pauls on Jan 13, 2017 19:29:17 GMT -5
That all looks good, but if your hard wheels are leaving flat bumpy bits that are difficult to remove (Ithink thats what you mean) then you may need a soft wheel around the 180 220 range to smooth all those bumps out. Never underestimate the importance of getting everything perfect (no Bumps, flat spots and scratches) when using the coarser grits, the finer ones will take ages or just never get there.
|
|
|
Post by pauls on Jan 13, 2017 19:21:02 GMT -5
Have a poke around in this forum, alloyavenue.com/vb/forum.phpjoin up, ask questions, they are a good bunch of people. Just about everything you need to know to melt metal.
|
|
|
Post by pauls on Jan 1, 2017 15:47:00 GMT -5
|
|
|
Post by pauls on Dec 28, 2016 14:07:17 GMT -5
No way, That price is way too cheap, people looking at those for $35 those will think a piece of dollar shop rubbish, put the price up and they will know they are getting a really good hand made replica.
Human nature is a strange beast, I have done the same at the market, put a small price on something and have it picked up and looked over and put down a dozen times, next week I tripled the price and it went while I was setting up and the person was over the moon about how great a bargain they had got.
|
|
|
Post by pauls on Dec 23, 2016 15:13:21 GMT -5
I'm old enough to know how big a quarter inch is so that does it for me too. As Zarguy said 5 cranks of the handle gets a nice thickness.
I'm an Aussie, we've been metric for 30 odd years so all my measuring is done in metric, so much easier, but when I started slabbing my slabs were quarter inch, so they still are. Go figure.
|
|
|
Post by pauls on Dec 23, 2016 4:15:30 GMT -5
He's using linear bearings, I wonder how long they will last before they destruct from rock sludge, I can't see too much thats earth shattering about his build.
I am toying with the idea of building a big saw and contemplated linear bearings for a very short time, If I ever do build it I think I will stick with the old rollers on rails design, if I went for slide bearings probably one of the graphite/nylon (Delron)simple bush type bearings, that stuff lasts forever, even in shitty gritty places.
|
|
|
Post by pauls on Dec 19, 2016 15:39:49 GMT -5
Those truing wheels are just steel, they operate by belting the crap out of the high spots as those teethy things whizz around. They wear out fairly quickly but replacement teethy wheels are cheap.
25 thou between the blades in that club article. No need to reinvent the wheel, everything you could need to know in that.
Thats a good idea having one of those in the club to save wear and tear on the plated wheels.
|
|
|
Post by pauls on Dec 16, 2016 18:25:39 GMT -5
I built one out of 5 inch blades, a mixture of continuous and slotted rim, nine blades in all, I could buy 3 packs of these blades quite cheaply, so I bought 3 packs of 3. I found my spacing is a bit wide for tumbling material it chews through the rock but leaves ridges which take a while to grind away, the space is probably about a sixteenth so is quite a thick ridge. I just feed water on top, it needs several nozzles or a wide slotted nozzle as the gaps dont allow the water to spread across the width of the grinding surface.
|
|
|
Post by pauls on Nov 25, 2016 15:23:10 GMT -5
Wow Dave so much information, fantastic. I always knew clay was complex but its not easy to find information thats accesible to amateurs, thanks for a great post.
|
|
|
Post by pauls on Nov 17, 2016 1:53:20 GMT -5
I built a cover for the big saw at the club from polycarbonate, I used "Weld On 16" like rockoonz and it worked perfectly. I just cut the plastic with the table saw applied the glue and it set as solid as a rock. That weld on is the bees knees for plastics. IPS corp. Gardena Ca. www.ipscorp.com
|
|
|
Post by pauls on Nov 5, 2016 15:49:47 GMT -5
I don't know about golf cart tyres but here in Australia a lot of tumblers use Go Kart tyres, apparently they need to be competition tyres because they have a harder composition rubber and harder side walls. Plug the hole in the donut with two rubber drain plungers back to back and bolted through the centre bit where the stick came out.
|
|
|
Post by pauls on Oct 14, 2016 2:41:09 GMT -5
Nice build. Constructive criticism not pickin on you. I would be concerned that those bearings are too exposed to the grit and water, you will notice the ones that captbob posted have the bearings outside the wet area. We have a couple of machines at the club that have bearings in the wet. The bearings are constantly being replaced, even well sealed agricultural bearings don't last all that long and they aren't cheap.
|
|
|
Post by pauls on Oct 4, 2016 18:29:58 GMT -5
Thats a really nice job on that heart you posted a photo of, excellent work.
|
|
|
Post by pauls on Oct 4, 2016 18:28:31 GMT -5
Ed, This method evolved from my instructing at the club, There were so many people struggling with getting a nice heart shape, especially around Valentines day, so I had a think about the procedure and decided to break it down into manageable steps and it mostly works. I haven't posted many photos at all on here, I do a bit of everything but don't take many photos of it, I might have to rectify that.
Ladysavvy, It sounds like you are well on the way, I would use a finer wheel to cut the cleavage, as I said mistakes happen a lot slower and scratches aren't as deep either. It sounds like you are doing the shape first with the cleavage then forming the dome, try making a domed triangle then cutting the cleavage. There's no easy way of getting the scratches out from inside that groove, its just patience and working with finer grits for longer to get it right.
|
|
|
Post by pauls on Oct 4, 2016 16:50:26 GMT -5
There's so much going on with a heart that its difficult to get all the curves right if you try and do them all at once, so break it down to a couple of easier steps. First make a triangle with two rounded corners and a pointy corner, this is your basic heart without the grooved bit at the top. Now shape the dome and make it into a cab, sand it up to the polish stage and then stop, so now it should be nice and smooth and free of scratches ready to polish. Now go back to the grinding wheel, don't use the coarse wheel here use 600 grit, that way any mistakes happen in slow motion. Carefully shape the groove and then sand the groove smooth and scratch free, you will need to use the very edge of your sander to get into the groove, when you are happy, polish. If you are making a double sided heart the second side is easier because you already have a nice even heart shape.
|
|
|
Post by pauls on Sept 30, 2016 15:26:46 GMT -5
Thats pretty much like the rock muncher I made up out of a rock drill. Hellish aggresive and really chewed into rocks but the channels in it rattled my hand that much that I could only use it for a very short time. I have since made up a gang saw blade setup like shotgunner said, works really well.
|
|
|
Post by pauls on Sept 28, 2016 23:51:54 GMT -5
Nice, well done. The green ones look like Aventurine Quartz.
|
|