Help and advise with Carbide tipped band saw blades

[steve_qix]

Hi !

I have a Sears 2 speed band saw - and I use it almost exclusively to cut printed circuit boards.

The board material is extremely hard (apparently, harder than steel) because I don't get a lot of cuts before the blade is quite dull.  I run the saw on its lower speed.

I've been thinking of getting a carbide tipped blade for the saw.  I know they are fairly expensive (although how expensive, I don't really know).  Would such a blade last a very long time?  Supposedly, carbide is harder than just about anything, but not having ever used a carbide tipped blade,  I just don't have any experience.

Any experience or advise in this area would be greatly appreciated.

Oh, the saw has a provision for hooking up a shop vac directly to it, and suck up any dust that might be produced during the cutting process.  I always use this when cutting, to avoid breathing any dust.

Thanks in advance !

Steve

[WA1GFZ]

Steve,
You should also wear a mask. A shop vac may put fine particles in the air that float around for a long time. The filter isn't that good.
I only use carbide blabes for all my saws. My 12 inch Deawalt chop saw has the same blade in it since I got the thing as a birthday present from my brother. It was used and he bought a nicer one with more functions. I used it to frame the inside of the house and every other thing like cutting pvc pipe. I've cut trim for the tub surround. I bought a new blabe with more teeth years ago. I may swap it out when I get to trim. I've also cut through a number of nails and staples.
The only thing I have that isn't carbide is my hack saw. I only use Lenox blades.
Steel is 6.5, glass is 7 on the rockwell scale if I remember. I would go for carbide if you can get it but buy a name brand. When I replaced the guy wires on the tower with 1/4 inch I bought some crap blades at home chepo. 3 or 4 cuts it it was ready for the trash. I bought a lenox 32 TPI that did almost the whole rest of the job. 4 sets of guys with insulators is a lot of cuts and that wire was hard. Do you know you can just make the boards with a string of holes along the cuts and just snap the board across the edge of a straight edge. Try it with a hunk of proto board. It is safer for your lungs and easier work.

[WQ9E]

Steve,

Carbide is very hard but also very brittle so do be careful to keep foreign matter away.  You must also be careful not to bang the blade against concrete, steel, or other hard objects or the carbide will break.  So careful handling is a must because these bandsaw blades are quite expensive.

I have never used carbide to cut anything but wood (on a bandsaw) but I do have some experience with it in that setting.  I have a 24" band saw in the shop and I have a couple of carbide bands for it.  Carbide blades are expensive and it is likely that the band will give out before the carbide does.  This metal fatigue is hastened by smaller wheel diameter.

I imagine carbide will stand up to glass epoxy far better than typical tool steel blades.  It does a wonderful job of resaw work and turning figured boards into veneer.  Have you also looked into bi-metal which is considerably cheaper but tougher than standard bands?  

P.S.  broken bands can be welded back together but this is only useful for a fairly new band that was damaged accidentally; an older fatigued band will just develop a new crack elsewhere in short order.

[Mike/W8BAC]

I suspect the material (printed circuit boards) is more abrasive than hard and that might be the reason the blades are showing shorter life spans than expected. I doubt coolant will help but you might try water to help flush the kurf and see if that helps.

Brazed carbide tipped blades should help but be prepared for a wider kurf and a less than smooth finish as the size of each tooth has to increase to accommodate the carbide insert. Good Luck

Mike

[WA1GFZ]

True about double kurf width so it might be more cost effective to drill holes along breaks and just snap the board. It is easy against a hard sharp edge like angle iron or aluminum.

[KA2QFX]

Steve,
   When I was working in the R&D world we cut all our G10 Glass/Epoxy using a foot operated metal shear for just the reason you’re experiencing.  The saw blade tooth is scraping away epoxy then glass. Once it hits the glass it’s keen edge is rapidly ground away.  Even a piece of dirty pine that’s been stored outdoors a while will take the keen edge off of my carbide blades, and they’re top of the line Freud.
The shear however has very little contact with the glass, pressing on the epoxy surface and fracturing the glass below. I don’t ever recall that blade getting dull. In fact, the office girls cut poster board with it all the time without any tear-out. 

I agree, if you can perforate a break-away line that’s the best solution. Let the other guy change drill bits! 

[WBear2GCR]

Carbide is king - short of diamond blades... another possibility in a small saw. Depending on the size of the boards you need to cut a "tile saw" will work wet, which is good with diamond saws...thin kerf, precise and clean... otherwise they work in small table saws... really small ones. Diamond will cut really fast, btw.

The other thing I would use is a shear. That's what I use to cut my PCBs and sheet metal. Clean, fast, "look ma" no dust!

I lust after one of those large shear/brakes that Harbor Freight and the other importers sell... my shear works up to ~12"...

                     _-_-bear

Edit: QFX beat me to the post by seconds!!

[KA2QFX]

Bear,
4 minutes 3 seconds to be exact. What do I win?

Mark

[W3RSW]

-a good, (used only once by a little ol' geezer) used carbide blade.

[N4LTA]

Steve,

I use an old Kepro Shear. You may find a used one. They work great.

I buy G10 in sheet for other uses - and the local company that I buy from uses a table type saw with very large blades - Like 24" or larger. the blade speed is very fast. I don't think you will ever get good blade life on a band saw.

I have a 10 " table saw and cutting just two or three 1/8" G10 sheets will ruin a good blade - even carbide.

Pat
N4LTA

[KM1H]

When I replaced the guy wires on the tower with 1/4 inch I bought some crap blades at home chepo. 3 or 4 cuts it it was ready for the trash

Frank, all my guys are 1/4" EHS here on the 4 towers with insulated guys and at the prior home. I tried the hacksaw on just 1 line and that idea was over. I picked up an old bolt cutter that had passed down from my great uncle to my dad and that did everything with one chop...it still does as I use 1/4" strand as messengers for the elevated hardline and control cables from each tower to the house as well as running AC to the garage and outbuildings.

It will be time to replace a few guy sections in a few months, rust is getting bad.

Carl

[WA1GFZ]

I used a saw because I didn't know my Dad had a big old bolt cutter till we cleaned out his house last year. The Lenox 32 TPI blade cuts right through cable and lasts a long time.

[w1vtp]

I vote for diamond blades  

These are shots of cutting a hole in my antenna range floor. Just use protection 

Al

[K6IC]

The PC Board houses use Router bits to trim boards to dimension.  They often shear the raw board material to rough size,  drill tooling holes in the raw board that has been sheared,  and every thing else is done from these tooling holes.

The board material is hard on the shear blade,  and it must be sharpened frequently.

Back in the day when most PCBs for our NA market were made in the USA,  one could buy used PC Drill and Router bits in sets of 25ish.  They were serviceable for hobbiest use,  they had just gotten too short to be sharpened.

Carbide is very brittle,  so it is delicate.  The small carbide drills would often break in a small drill press -- they were intended to be used on a CNC table.  Use protection,  as noted above.

For protos,  our company used phenolic board,  but many of our protos were single-sided analog designs ...  the phenolic is drill/router friendly.  double-sided and multilayer boards were always sent out for proto.

Carbide IS king,  and not horribly expensive.  GL  Vic

[WA1GFZ]

Al, Where was that picture taken? Nice chamber. Also be careful with particles coming off the foam when you handle it.

[w1vtp]

Frank

That was back in 2005 -- it's a near field antenna range.  I bought the stuff and supervised its installation.  It's my "baby."  Yes, we were much aware of that metal residue and carefully inspected the absorber afterwards.

Here's the finished range minus the phi positioner where that shiny aluminum is.  It does planar, cylindrical and spherical near field scans

Al

[WA1GFZ]

may I ask what company?  nice job
We have 6 chambers 2 are mode tuned.

[w1vtp]

may I ask what company?  nice job
We have 6 chambers 2 are mode tuned.

I work for Raytheon Tewksbury ma  This is the near field range my other range is a far field range

Thanks for asking

Al