Is a variable speed grinder essential?

[stonecutter]

Re: Is a variable speed grinder essential?

I wanted to post this in case anyone want to polish material but doesnt have a variable speed grinder.

Router Speed Control

[stonecutter]

Re: Is a variable speed grinder essential?

You should get a rigid backer, since you are seeding your form with aggregate. But backers are pretty cheap... Why not get them both.

[RichC]

Re: Is a variable speed grinder essential?

One more question before I buy guys.
I'm buying these discs ATS Premium Wet Diamond Polishing pads discs 100mm (4") Granite Marble Concrete Terrazzo 9 piece set: Amazon.co.uk: DIY & Tools
Should I buy a rigid backer pad:

http://www.amazon.co.uk/gp/product/B00DSR73PW/ref=ox_sc_act_title_2?ie=UTF8&psc=1&smid=A1INGGQMSQ4FCZ

or a flexible backer pad
ATS Flexible Backer pad for 100mm (4") Diamond polishing pads discs QRS hook and loop Velcro: Amazon.co.uk: DIY & Tools
Also, is the M14 the standard fitting size for angle grinders?

Thanks

Richard

[RichC]

Re: Is a variable speed grinder essential?

Thanks again guys!

C'mon now that's just silly. Get pads that fit the grinder/ polisher.

Might as well buy myself a 4" grinder then!!

[Gulf]

Re: Is a variable speed grinder essential?

The only way I'll get my hands on stained glass is by visiting the local church at night with a brick
I was considering filling most of the form except the edges and then making up a mix with a high density of crushed glass for the edges in the hope that most of it would stay there! Sound like a plan?
I'm also going to make up a sample with gravel and see how the aggregate comes through when polished....so far Ive only made sand cement samples and not polished them, just to get and idea for the colour

The bands/edges don't have to be a perfect match for the surface. They can be "contrasting" and still look great!. As far as preseeding the edges is conserned, that is up to you. What ever you come up with will be just fine .

[stonecutter]

Re: Is a variable speed grinder essential?

C'mon now that's just silly. Get pads that fit the grinder/ polisher.

[RichC]

Re: Is a variable speed grinder essential?

Will 4" pads fit on a 9" grinder ok or do I need to pick up a small grinder?
Thanks

R

[RichC]

Re: Is a variable speed grinder essential?

If you are are using crushed glass bottles etc., you will not end up with flat edges to apply to the bands. Again, I used broken colored glass window panes. Maybe, you can find some that is a similar colored to what you plan to seed the top. They may not be a perfect match, but maybe an accent or complimentory color. If you add any aggregate larger than sand, that will make a big difference in the look also.

The only way I'll get my hands on stained glass is by visiting the local church at night with a brick
I was considering filling most of the form except the edges and then making up a mix with a high density of crushed glass for the edges in the hope that most of it would stay there! Sound like a plan?
I'm also going to make up a sample with gravel and see how the aggregate comes through when polished....so far Ive only made sand cement samples and not polished them, just to get and idea for the colour

[Gulf]

Re: Is a variable speed grinder essential?

....... I was wondering how to 'seed' the edges... Haven't heard of latex caulk before so I'll need to check they out. Why that particular product? I would have expected it to pull off with the formwork and leave a depression in the countertop but it obviously doesn't? Could a small dab of superglue achieve the same thing?
Also, is that just a bead of standard silicone that you used to fill the sharp corners of the form work? I was trying to think of a good way to chamfer the edges of the finished counter

Thanks Rich,

I had not heard of latex caulk being used for this either. It may have, but I never ran across it in my little bit of research. It doesn't take but a very thin film of the latex caulk to hold two flat surfaces together. I would not use superglue, I don't know if that would work. I did not have the first piece of glass or prefilled and polished seashells pull away from the concrete. I did use silicone to chamfer the corners, but you will notice that the hand polishing blocks will easily add a little more chamfer.

If you are are using crushed glass bottles etc., you will not end up with flat edges to apply to the bands. Again, I used broken colored glass window panes. Maybe, you can find some that is a similar colored to what you plan to seed the top. They may not be a perfect match, but maybe an accent or complimentory color. If you add any aggregate larger than sand, that will make a big difference in the look also.

[deejayoh]

Re: Is a variable speed grinder essential?

I stand behind my previous post. It may have worked fine and dandy for you, but I won't recommend doing stuff the way I do it, if I had to modify technique and tools outside of standard safety practice...even if the results achieved are spectacular.

Lol. Well said. I wasn't taking your comments any way other than as recommending standard practices.

[RichC]

Re: Is a variable speed grinder essential?

Thanks for the advice guys! That's a beautiful job Gulf, turned out great. I was wondering how to 'seed' the edges... Haven't heard of latex caulk before so I'll need to check they out. Why that particular product? I would have expected it to pull off with the formwork and leave a depression in the countertop but it obviously doesn't? Could a small dab of superglue achieve the same thing?
Also, is that just a bead of standard silicone that you used to fill the sharp corners of the form work? I was trying to think of a good way to chamfer the edges of the finished counter

[Gulf]

Re: Is a variable speed grinder essential?

Rich,
Since you are going to pour in place, you can still use one "trick" of an upside down pour. That is preseeding your counter edgings. (Down here, we call them bands).





I used colored window glass for mine. (Not a lot, since I had a lot of other stuff going on.) I went to a local glass company, who was glad to sell me a couple of broken pieces of their stained church glass drops, cheap! To pre seed the bands I just glued the glass pieces to the form with a very slight dob of latex caulking. When the form is removed, the caulking releases easily from the form.



If you can obtain some church glass that is simular in color to your broken glass for the surface, it will help the bands to match. I shaped my glass shards with a pair of "wire dikes". The hand pads that Stonecutter mentioned are crutial for polishing the bands. And preseeding the bands will save you a lot of time.

I can't stress enough the need for the GFI as Dennis mentioned. I also decked out in what I call Full PPE (full rain geer , rubber boots, face sheild, and rubber gloves). Also, wether or not is a double insulated grinder/polisher or not, do place the plug in higher than the lowest point of polishers cord!

[stonecutter]

Re: Is a variable speed grinder essential?

Wait a minimum of a week, longer with cooler temps, or you will tear out your seeded aggregate and the surface won't polish well.

[RichC]

Re: Is a variable speed grinder essential?

Thx guys, back to grinder with speed control then never polished concrete but well used to power tools! Do you need to start this process shortly after pour or is it best to wait longer ? Or can I leave it until I find the time to get to it?

[stonecutter]

Re: Is a variable speed grinder essential?

My experience was that you run the speed up to where it feels like it is working, it's pretty easy to gauge.

FWIW, I didn't feel unsafe using the grinder. Rubber gloves +rubber boots + GFCI. Only popped the fuse once and I knew why.

I'm not trying to be a safety cop with grinder use, that would make me a hypocrite in this dept.

None of my grinders have guards or handles. I don't feel unsafe, and I have been doing it for years with no problem. That doesn't make it a safe practice...especially when people that aren't use to working with them that way are trying a technique for the first time.

I stand behind my previous post. It may have worked fine and dandy for you, but I won't recommend doing stuff the way I do it, if I had to modify technique and tools outside of standard safety practice...even if the results achieved are spectacular.

Let the readers/builders use discernment.....