[sajjt]

Originally Posted by shyamhegde

Price is now increased. Bought one for a friend at Rs.340/- yesterday from Mark Telecom, SP Road, Bangalore. No warranty, only testing. Same model I have been using for 5 months and it is fine on a moderate usage.

Attachment 422937

The same model I've bought it from Ebay for 558+50 for shipping 2 months back. It was out of stock in our place and I need this urgently But its OK for the price for moderate usage. B&D will cost around 1.1K with 6 months warranty and MRP is around 1.5K.

Heat guns can be used for de soldering chips very easily especially on ICs having pins all four sides where desoldering is very difficult without adequate tools I've seen many mobile service stations using this for the same purpose. But it can't be used for soldering. Its a wonderful tool for joining thin copper tubes as Sagiitk sir said as its as good as a low power blow torch if you have some attachments. I've tried even on thin plates too, only thing is you should use a leather glove for the protection else can make sure of sore fingers.

[Mr. Nobody]

@ shyamhegde got the heat gun same model as yours . haggled down to 330 rs .

[AWD]

Originally Posted by Jaguar

Picked up the Bosch Drill Tool Kit from there for Rs.3500

Attachment 150699

I bought the same set for a 100 Re less.

Out of the 3 types of bits pictured, which ones are used to drill in Marble?

[shyamhegde]

Originally Posted by Mr. Nobody

@ shyamhegde got the heat gun same model as yours . haggled down to 330 rs .

That's good to hear Puneet. Congrats. Hope that works through your project.

[Jaguar]

Originally Posted by AWD

I bought the same set for a 100 Re less.

Out of the 3 types of bits pictured, which ones are used to drill in Marble?

I am not too sure of marble. Have used the drill only for wood and the brick walls of my home.
As per Drill bits - the different types explained a masonry bit is required for stones and I don't see that type of bit in the bosch kit. Maybe some tool gurus can shed more light on this.

[AWD]

Thanks fo rthe info. but in the pic. 3 types of bits are figured. Out of these which ones could be used on marble?

[Sankar]

Originally Posted by AWD

Thanks fo rthe info. but in the pic. 3 types of bits are figured. Out of these which ones could be used on marble?

The shiny ones i guess. Those are the bits to be used on concrete, i guess it would work for marble too. Bits for concrete has a bit of added reinforcement at their tips, you can see it when you look at them.

[AWD]

That is the ones figured in the middle. These are hammar headed I guess.
Bosch should supply proper instructions & usage details with the kit.

[sajjt]

Originally Posted by AWD

Thanks fo rthe info. but in the pic. 3 types of bits are figured. Out of these which ones could be used on marble?

For marble and granite bits entirely different are separately available. It doesn't have sharp tips but with a circular/hollow tips. you cant use the concrete bits to marble and it will get spoiled once you try with a marble surface.

[AWD]

Thanks, I can't afford to spoil the marble because those are huge slabs 8x6ft. & pretty old. Don't get the same pattern now.

Can the bits that are used on tiles, used on marble? Bosch has mentioned one of the bits pictured above can be used to drill tiles.

[DerAlte]

The middle ones - silver colored. The bottom set is wood bits (with a tiny pyramid-shaped hole center stabilizer), the top set is for metal.

For marble, be sure to use the impact setting and slow speed. To prevent bit from wandering at the start, mark the center of the hole by lightly tapping a thick nail with a hammer till you get a small depression.

[Thad E Ginathom]

Never had any marble to drill, but I don't think it is very hard like, for instance, granite. Possibly it may even be softer than ceramic tiles?

Whatever you try, go slowly and gently, for fear of breaking the marble. I would not use the drill in hammer mode.

Don't worry about spoiling the bits: worry about spoiling the marble, which may be irreplacable. Bits are relatively cheap and easy, even the fancy ones.

<Crossposted with DerAlte>

The bottom set is wood bits (with a tiny pyramid-shaped hole center stabilizer), the top set is for metal

Basic twist drills can be used for either, as long as they are hard enough. Cheap ones may be good only for wood.

For marble, be sure to use the impact setting and slow speed. To prevent bit from wandering at the start, mark the center of the hole by lightly tapping a thick nail with a hammer till you get a small depression.

A centre punch is the tool for the job, but, I worry about breaking the stuff. I don't do this on ceramic tiles. I use adhesive tape (something thick like duct tape is idea) to help keep the drill point in the right spot. I'd certainly try drilling marble without hammer, just to be safe[er].

.

[sajjt]

Originally Posted by Thad E Ginathom

Never had any marble to drill, but I don't think it is very hard like, for instance, granite. Possibly it may even be softer than ceramic tiles?

Whatever you try, go slowly and gently, for fear of breaking the marble. I would not use the drill in hammer mode.

Don't worry about spoiling the bits: worry about spoiling the marble, which may be irreplacable. Bits are relatively cheap and easy, even the fancy ones.

<Crossposted with DerAlte>Basic twist drills can be used for either, as long as they are hard enough. Cheap ones may be good only for wood.
A centre punch is the tool for the job, but, I worry about breaking the stuff. I don't do this on ceramic tiles. I use adhesive tape (something thick like duct tape is idea) to help keep the drill point in the right spot. I'd certainly try drilling marble without hammer, just to be safe[er].

Yes centre punching tool is the one to be used for getting started with. Even the plumbers used to do this trick before they start with drill. If the punch tool is sharp, a small tap is more than enough to make a marking and make sure that you are not hitting it with full strength. One ceramic tiles top coat glazing is very slippery and very hard where the punch is very effective.

If you go to any hardware shop and ask for a granite bit with the desired size and make sure that the same bit is with you else you can buy it. Marble/granite sufaces are tougher than other surfaces and most of the bits are with the so called diamond tips. These are slow speed bits, so take care of the drill speed if you can manage.

[DerAlte]

Originally Posted by Thad E Ginathom

... Possibly it may even be softer than ceramic tiles?
Whatever you try, go slowly and gently, for fear of breaking the marble. I would not use the drill in hammer mode.
...
<Crossposted with DerAlte>Basic twist drills can be used for either, as long as they are hard enough. ...

Originally Posted by sajjt

Yes centre punching tool is the one to be used for getting started with. ... One ceramic tiles top coat glazing is very slippery and very hard where the punch is very effective....

I was commenting w.r.t. the masonry bits (that's the correct term, I guess) provided in the set. I have used them on marble with the drill in impact mode - it conveniently pulverizes the marble crystals without cracking the marble. One must lubricate while drilling - tricky on vertical surfaces; on horizontal surfaces I use a rag to create a pool of water around the hole being drilled.

I normally don't use a center punch on tiles (cracks the brittle coating more often than not, leaving unsightly spidery cracks); marble maybe. It is difficult to estimate how hard to tap on a tile without doing damage, and anyhow most home DIY people don't have a center punch. A normal thick GI nail is softer, doesn't crack the surface of marble and tiles, and leaves a dimple just deep enough for the bit to bite into and not wander. @thad, your masking tape trick sounds very interesting, must try it some time!

Granite bits are coated with diamond dust to grind the material, rather than shattering it with impact. Should be good for marble too - marble is softer than masonry and cinder blocks (which are granite particles agglomerated with cement). No need to use impact setting on the drill, and lubricating with water helps in prolonging bit life.

Granite bits are usually annular to reduce the amount of diamond dust needed. BUT, the main problem with granite bits is hole starting: center punch will not be useful unless one draws a circle and punches along it, and drilling is best done with the object surface horizontal. Most professional granite drilling is done using a drilling jig.

@thad, the wood bits work best for wood. The pyramid centers accurately (the marble top layer on the Lotus Temple in Delhi was laid by carpenters - just because carpenters are much more accuracy-conscious than masons), and the two resultant spikes on the tip cut wood across fibre to make a neat hole. A metal bit just whirls around instead of cutting neatly, takes longer, heats up very early and burns the wood (can't use water to lubricate the drilling). Metal bits are fine with MDF, but for real wood (like Teak, Rose-wood or Sal) one reduces post-processing drastically using wood bit. There is another type of wood bit - spade bit - but those generally come in sizes larger than 8mm.

[Thad E Ginathom]

Interesting experience. Can you illustrate the drill bits that you are talking about, or give a link, so I can be clear? Once upon a long time ago, I used to drill holes in pieces of metal for a living, and the drill bits we used, were standard high-speed-steel (HSS) twist drill bits. There are several different bits that are specific to wood, though.