problem cutting 16x16 porcelain tile

[Rufous]

Hi
We're installing 16x16 porcelain tile on our kitchen/dining floor over Ditra membrane and are following Schluter recommendations re trowel size and kind of mortar to use. Huge project what with all the necessary prep work including leveling the 1.25" double layered plywood subfloor, renting a pickup to haul a pallet of tile from a HDepot 3 hrs away, etc. Anyway.... now the whole tiles are thinset mortared in place and we're ready to cut and set the ones that fit along the perimeter--the ones that need cutting. I'd researched this project thoroughly on the web...I thought...Rented a wet saw (Felder Tile Master 1.5 horsepower--big, heavy, on an X stand) with a diamond blade for a day's cutting.We didn't get very far.....The blade jams on the tile throwing off sparks and powder...the blade literally grabs the tile as it chews into it, pulling it away from me as I try to guide it slowly forward, and then jams....stops spinning (scary) so I immediately shut off the motor. The tile meanwhile has cracked on both sides of the 6" long cut. The cut itself is clean but I had to abort the cut cuz of the jamming. Debris (sharp shards) from the failed cut are in the groove the blade cuts thru. I called the rental/hardware store...they thought the blade might be loose. Uh uh.....tight as can be. Tried another cut...same problem. I took the tile to the rental store to show them what the cut looked like.They said the blade probably needed replacing.The store owner actually came over to the house with the new blade and installed it. I tried cutting a tile with the new diamond blade, but it cut worse--chipped cut line--and then jammed into the tile sending off sparks. The owner said the material was too hard for the blade to cut...asked if the tile came w/ cutting instructions. No. The box said "glazed porcelain ceramic tile. Heavy."I told him I'd read somewhere that you need a diamond blade to cut porcelain tile. He said he'd never seen this kind of tile, that it wasn't ceramic, and that his wet saw couldn't handle it. I took the saw back to his store and he refunded our money. Now what........?
I'm wondering if there's a different kind of diamond blade that should be used for porcelain tile...or whether a more heavy duty (3 horse power?) wet saw motor is needed. Web tile equipment sites mention Hot Dog and other tiles that claim to cut porcelain, but after this experience, I'm leary of what might be hyped claims. I'm thinking of asking the rental owner if I can rent his wet saw and I provide the proper blade... Or we'll probably need to rent a tile cutter in Indianapolis to get this job done....but I need to know what to rent. I might end up haling the tile to Lowe's and have it cut there at 25 cents a cut on their big tile cutting saw.This was our last resort...but it's sounding pretty good right now....Any advise is hugely appreciated.THANKS!

[Davestone]

You robably need a (Porcelain) specific blade.Porcelain is almost twice as hard as regular ceramic, and what you described is typical.Also the plunge(depth of the blade into the groove on your table) may need to be adjusted up,that's that black knob on the left side of the saw, you unscrew it a little and lift the head(the part of the saw with the blade) up so the bottom tip of the blade is only about 1/4" below the face of the table in the groove,then screw it back tight....and keep the groove clean.

[tile mom]

Hi- I am no pro but just wondered as I read your post...do you have enough water in the tray to let the pump suck up enough to keep the blade cool? The only time I have seen sparks when cutting was when the level of water got too low and so not enough water was going thru the pump to cool the tile and blade. Anyway, just a thought. I work with porcelain all of the time, but as Dave said, you do need a porcelain blade. Also, you can't shove the tile thru the saw, just let it go thru smoothly...Still shouldn't take but a few seconds to cut the length tho. hope any of this is helpful.

[camachinist]

Welcome!

As the moderator said, likely (overwhelmingly likely) the problem was the blade. Porcelain tile is not "porcelain glazed ceramic tile". The former is solid porcelain, which is much harder. The glazed tile only has a hard wear surface, which is thin and easily penetrated by the blade made for it.

You had a good saw; it just wasn't set up properly for the job. Surprised the rental store (which likely rents to contractors too) didn't know that. IIRC, a similar blade is used for granite, which is also very hard.

Set up properly, the saw should just require guidance, not force, to cut. You'll develop a feel for the feed and a light touch will be all you'll need.

I'm not a tile setter but have cut a fair amount of concrete and stone in my work as a machinist (testing equipment) and that's what I've observed.

Good luck. Sounds like a DIY job you'll be proud of for many years

Pat

[Rufous]

Thanks for your comments/suggestions Davestone, tilemom and Pat. I don't understand the rental place owner being puzzled by porcelain tile....I've read it's in great demand nationwide....and, yes, they rent out equipment to contractors.
Package says "glazed porcelain tile" made by Sardinia Ceramics. I was typing from memory and misquoted instead of checking the box. I'm pretty sure it's the real McCoy.
If I can't find a rental wet saw with a porcelain blade (crunched for time...daughter and family visiting next weekend) it just occurred to me: what if I lightly score the glazed side of the tile...say 1/16"... with a table saw using a masonry blade...and snap the tile in 2...??? Could even give both sides a quick pass if one won't do it....Will give this a try and see what happens.I could get by with just straight cuts with the cut sides disappearing under baseboards.Then tomorrow get on the phone to track down a proper rental wet saw with a blade that cuts porcelain if my experiment is a bust.

[Lazarus]

Interesting.....If you used a "Hot Dog" blade from HD or Dal....and didn't rush the cut, I think you would be OK......I cut porcelain all the time with that same saw, and have no problem.

[poidog]

it's not the saw. i ran into this cutting 16 x 16 porcelain tile thought it was the tile being too hard, blade loose or quality. on the back of my tile there was an 1/4" by 3/4 " label stuck on with adhesive - small but deadly. it yanked the tile, sparks flew, shards exactly how you describe. after the 2nd tile scare i went through the debris and found a rolled up gummy label. i made sure to remove all the labels off the tile before cutting - whew!

[Rufous]

Follow-up report--years ! later...but info still useful

Did some google research and found out that I needed a 10" DESIGNATED PORCELAIN wet cut diamond blade. Called Lowe's in Indy...they had one in stock: $70.

Asked the owner of the local rental equipment if he'd rent me his wet cut tile saw if I supplied the blade. He was fine with that.

Bought the blade. I'm writing this from memory...Can't remember the brand (gave the blade to my son who was tiling his kitchen floor), but the blade was yellow and $$--a beauty with nifty curlicue cutouts along the edge at intervals!

What a difference! The new blade cut through the porcelain tile cleanly and effortlessly-- like butter. The job was done in no time....

The whole project was worth the time, $$$, and effort. 4 yrs later and it looks like new. The tile is easy to maintain and looks great all the time. Highly recommend tile flooring for ANY room...works in formal and casual settings...but you have to choose the right kind/design for it to work.

More than you want to know.....

[Lazarus]

Sounds like a "J-Slot " blade. Got one on my Felker....