Mikey98118

So the 220V 3" angle grinder arrived from China through Alyexpress.com (a few days early). The first thing I noticed was that its cast aluminum gear housing was clean and sharp; no flaws or inclusions. The motor and gears are fairly quiet. Even though it is meant to run on 220 volts, you can plug it into a 110 volt outlet, with its speed control turned up full (6), and it runs just fine; doing this is the equivalent of running the grinder speed control at half speed (3) from a 220 vold outlet. So, you can use this tool while you wait for a 110 to 220 voltage converter (which you can also order from China, or buy through Amazon.com) to arrive. The only disappoint I have so far, is that the The mandrel's collet only allows 1/8" rotary tool accessories to be mounted (this grinders threaded spindle is hollow, so that it can allso be used as an angle head rotary tool). There is plenty of room in the angle grinder's spindle to mount a 1/4" collet, if you can find one that fits. The motor is mounted in a plastic case, which I find easy to wrap my long fingers around. Most people would probably prefer using both hands, and at full power that would be the only safe position to use. So far, I am delighted with this product, which costs no more than one of the cheaper rotary tools on Amazon.com. However, you must be prepared to put up with some hassle when buying the tool. None of these sites were developed buy people who knew what they were doing. Also, there is a wide range of pricing for what at first appears to be the same tool; don't believe that for a minute, and become "penny wise and pound foolish." If you want to see how cheaply you can come by a second tool, fine; you can always use it for parts.

Argh! I need a cup of coffee before going any further with this.

Stop it, stop it!!! want to be aggravated by this problem, and you're making me grin. Soon I'll be laughing out loud

You are welcome, Steven. All the lurkers who also need that question answered thank you for asking it

It is good to keep the misconceptions down

AFB, It is a one-off for most people. Since fumed silica is also used as a binder in various refractory mixes, and as binder to mix with ground zircon powder, in heat reflective coatings etc., a gallon jug isn't all that much for some people. Steven, For your use, that jug is A Lot!!! You must remember that commercial "colloidal silica" solutions are sold as full of the silica as possible, to offset shipping costs; not because the supplier supposes that their customers will necessarily use them "as is"; some do, and others don't. So, why would a small amount of fumed silica do the job? Because the thickness of the sheath of glass coating left on the individual ceramic fibers is only a few nanometers thick. The solution is drawn along the fibers by capillary action, leaving the fumed silica as a surface film after the water drys out. Where the individual fibers cross one another, they collect in a large enough lump to act as a weld; this is how ceramic wool is rigidized with colloidal silica (well, once it is heated to red incandescence). So, think in terms of cups of fumed silica in a typical spritzer bottle. Do not mix up any more rigidizer than that at a time, because once mixed, the solution must be kept from freezing in your garage. If allowed to freeze, the solution must be thrown out; it will never be colloidal again.

No; colloidal silica simply consists of silica particles small enough to stay in solution, when mixed into water. Fumed silica is made up of molecular chains, a few molecules long; they are, by nature, tiny enough to qualify for this use. Simply mix them into water to suit, and add a little food die to the solution, to enable you to see how well your rigidizer is doing its job. The next question is usually "how much fumed silica to how much water." You will be glad to know that "to suit" means exactly that. If your solution ends up to thick to spritz, just add water until it will. If too little silica is present in the water, it does a weak job of rigidizing, but you can repeat the process as many times as you want. So, anyone would have to work very hard to mess up So, how will you know if you get enough rigidizer on the ceramic fiber? Once you think you have enough, using the visible evidence provided by the food die, heat the insulation to red hot, using your burner. Once cool, use the touch test to decide whether you are satisfied with the result; if not, just repeat the process as many times as desired, until you are

So, ye wist not to use it any other way?

Oh, good one, Frosty! And written "in tune with the music," so to speak

And if not tongue in cheek, I use them wistfully; for these good things are just not in the cards. "To ere is human" and even worse, historic. The more new products that come on the market the more errors in judgement must be corrected On the plus side, at least the new gas forges get hot enough. So, before we shake a finger, it is good to remember all the 'red hot' forges that we used to see What I like best about your idea is choice; he can use it to save fuel most of the time, and still have space for tall objects, likr helmets, bowls, or crucibles when needed.

Getting back to his point; it is a very good point. This little mess has been bugging me for a couple of years. And my answer to his problem was sloppy, because I only have a hazy idea of a workable exact solution. The best I can say is what will lesson it. Not precisely why some burners in some forges experience it. What I can say precisely is unhelpful, but here it is. "Your burner is a little weak." It's not a lot weak, or your forge would not be getting to yellow incandescence with it. How's that for cold comfort? Unhelpful all over the place, right? So, we muddle along, with advice that can at least help; here is more. The mixing tube on your burner is too long, which weakens its flame somewhat. So shorten it down to nine times its diameter. And now you are being asked to modify your forge's burner by someone you never met; what's the chance that such advice is inviting? And furthermore, you will still need to increase the insulation in your forge's ceiling, so my advice is still less welcome; in your place, I would feel quite reluctant to take it. Finally, I cannot guaranty you that my advice will work out perfectly for you. I can only state that "in my vast experience..." blah, blah, blah. What a pickle! What to do? Well, you could just act on the first advice, and see how it works out... And finally, I could point out that your burner is top pointed and pointing straight down, which invites this problem. Manufacturers should mount their burners up high on a side wall of box forges, in order to avoid it. How's that for adding insult to injury? Now, aren't you sorry you brought up that objection? But, I'm not. It is long past time this mess got addressed. Anyone else want to "step up to bat, and take a swing"? Ugh! how about "...top mounted, and pointing down"; that should make better since

I think they stopped selling the burners, first. And you're right; they were the best part of the deal.

That is sad. at least there are a few other good commercial forge designs still available on the low end of the market, even if the very best deal isn't around anymore. A couple of the all stainless steel oval forges are still worth picking up, although you would be well advised to replace their burners...

No dispute here, but I am merely agreeing that a small air gap (less than 1" thick) will have some insulation value. And since it would also help to reduce the internal volume on what I consider to be a an overly tall internal volume, it would probably serve a double benefit. On the other hand, I like that recuperative forge scheme, being an impractical total over-doer at heart, my own self

Yup! And since getting the two surfaces to mate perfectly would probably be a pain, ain't that nice? So, if he chooses ceramic board, or Morgan K 26 bricks, he could just drill small holes in the top plate of his forge shell, and drop screws through them, and screw them into a suspended ceiling, to hold it in place.

I think you answered your own question, when you stated "...but the insulation was a bit lacking inside the forge." I noticed that it is the top of the forge, rather than the burner that is turning red. Therefore, it is unlikely that heat is backing up much between the burner and the opening. So, you will need to add another layer of insulation on the ceiling, with another flame coating over that. You might consider using ceramic board, rather than ceramic wool, for the purpose.

If you set up the forge as a radiant oven, than perhaps nothing will be lost by the "cold spot," where you might continue to set your work. For, it would not remain cold, but would remain unlikely to be impinged by the burner's flames, and therefore unlikely to contribute to scale on work surfaces. Just a thought.

Lee, Repurposing is just one goal. We all do what we can to simplify burner construction. Meantime, we do what we can, never knowing who in the wide world will come up with a better plan

I suspect that manipulating the patterns of multiple flame orifice ceramic heads and stainless steel flame retention nozzles, will be the next big improvement in burner design. The clever part will be in keeping the construction simple enough to interest novices. So, repurposed parts will remain key?

When it comes to burner design, I think you're on a roll

I never enjoyed TIG welding. One of the things that was so enjoyable about oxyacetylene welding, was that it was just that little bit slower; slow enough for mirror welding. There is nothing like fixing nasty messes on the hidden side of marine pipes, to mollify a worried boss

Is there anything we can't get addicted too? My last gas weld must be thirty years in the past; I still wanna...

The temptation to "just weld it together" bugged me for several years. So, I gave away all my welding machines to friends; no more temptation...at last Okay, that's a lie. There is still some temptation left, but I can just lay down and be very still, until it passes

We both resemble that remark

So, how would you know what fastener to use and how to use it? Just Google "fasteners." Then Google each fastener that you are interested in; some provider while list instructions on pop-riveting, etc. in order to encourage you to purchase their product.