Need Angle Grinder Advice

[JIMMIEM]

I have to undercut a brick fireplace hearth so that I can slide the 3/4" hardwood flooring that I am installing under the brick. There are better tools to make this cut than an angle but they are either too expensive to buy or not available for rental. I am going to go with an angle grinder and a diamond blade. I don't need a top of the line tool as I don't anticipate much use for it after this project. Need recommendations for brands, power and size. Just want something that will get the job done....doesn't have to be very fast as time is not a factor.

 

[Mr. Brooks]

Harbor freight oscillating tool or angle grinder with appropriate attachment. Only say this since you don't want to spend a lot and don't forsee using it afterwards.

 

[Askme42]

Harbor freight oscillating tool or angle grinder with appropriate attachment. Only say this since you don't want to spend a lot and don't forsee using it afterwards.

I agree. My HF grinder actually treated me decent but I burned it up when I started using it more than anticipated. Replaced it with a metabo and love that thing.

 

[JIMMIEM]

Harbor freight oscillating tool or angle grinder with appropriate attachment. Only say this since you don't want to spend a lot and don't forsee using it afterwards.

I have a HF oscillating tool and a Bosch good one. I didn't know if this tool would do the job....some say yes but will take a loooooong time. I saw the HF grinders in the store but don't which one will work....the regular or heavy duty.

 

[JIMMIEM]

I agree. My HF grinder actually treated me decent but I burned it up when I started using it more than anticipated. Replaced it with a metabo and love that thing.

I called a masonry supply store and they had the Metabo for $160....a lot of $ for a one time project. Which HF grinder did you have 4" or 4 1/2", regular or heavy duty....they have several....the employee wasn't much help. I just have to do a cut 1/2" to 3/4" deep.

 

[Vegaman_Dan]

I think I'd be tempted to rent the tool you need for this one time job at the box store. Might get something a bit bigger and more power to get through that brick quicker.

 

[Askme42]

I called a masonry supply store and they had the Metabo for $160....a lot of $ for a one time project. Which HF grinder did you have 4" or 4 1/2", regular or heavy duty....they have several....the employee wasn't much help. I just have to do a cut 1/2" to 3/4" deep.

4 1/2 heavy duty. I got the metabo online dot remember how much.

Where you're going to have trouble is the HF unit overheating. If you feel tw machine getting hot set it down for a good whole and come back later.

 

[Givl Reggin]

I have to undercut a brick fireplace hearth so that I can slide the 3/4" hardwood flooring

Scribe the flooring to the brick - cutting brick inside is a messy job!

 

[strutaeng]

Can't you just leave it ****-up against the brick?

I installed wood laminate and left a small gap at the brick fireplace, which was sealed with color-matched sealant. This was easier for me than trying to leave all the planks exactly tight against the brick.

Do you have a photo of the situation? It seems unconventional to cut into that brick, not to mention all the dust you are going to create.

As far as grinders, get a DeWalt, Bosch, Milwakee or similar. They are usually 50-60 bucks and nice masonry disc (not the abrasive type).

Good Luck

 

[Trey T]

^I think he's going for a certain look. I've seen it before on This Old House and it looks very nice and clean

 

[fnieto]

Cheap grinder with a decent diamond blade will make short work of this. Just know you will be producing a lot of dust. Maybe someone can follow along with a shop vac to help control some of the mess.

 

[Mr. Brooks]

Yeah I have seen some angle grinder shields with built in dust control (hole to hook up shop vac/vac)

 

[rlitman]

Yeah I have seen some angle grinder shields with built in dust control (hole to hook up shop vac/vac)

THIS. It is called a tuckpointing grinder, and you can almost certainly rent one. No dust.

Or just get a $20 4 1/2" HF grinder, add a cheap diamond wheel, and make a HUGE mess.

 

[bcradio]

The absolute first thing you need to determine is how deep you need to cut. 4 1/2" grinders do not allow for very deep cuts, but if you don't need to go deep then you will be fine.

You can then size the grinder you need to the cut depth (4.5", 7", 9").

Also, grinders are useful for more than just cutting concrete. I would get a mid-range quality one because you may find other uses for it.

 

[tshetter]

The flooring guy I used to work with would use a scrap piece of the new flooring as a height gauge and use an oscillating tool to cut door jambs and baseboards.

Worked pretty well for him and went really fast.

Never did it myself, so I cannot speak to how dumb-proof it is or how much skill he possessed doing that.

 

[JIMMIEM]

I was originally going to frame the hearth with the flooring but I like the 'clean' look that you get when the flooring runs under the brick. I can cover the area with plastic to help contain the dust and also use a shop vac to grab the dust. OR...The concrete pad that the hearth sits on extends out 3 1/2" past the front of the brick and I was thinking maybe I could add another row of brick here and leave the 3/4" gap under the front edge of this new row for the hardwood flooring.....better plan?

 

[Mr. Brooks]

I was originally going to frame the hearth with the flooring but I like the 'clean' look that you get when the flooring runs under the brick. I can cover the area with plastic to help contain the dust and also use a shop vac to grab the dust. OR...The concrete pad that the hearth sits on extends out 3 1/2" past the front of the brick and I was thinking maybe I could add another row of brick here and leave the 3/4" gap under the front edge of this new row for the hardwood flooring.....better plan?

Someone smarter than I will address your alternative option, but I will say that tarps or plastic only minimally help the dust issue. I've seen rooms that needed to be repainted due to that mortar, grout, and tile dust. If it were means didn't have a dust attachment I would make it a two man job with someone with a power shop vac right next to me at all times. Good luck sir.

 

[JIMMIEM]

The flooring guy I used to work with would use a scrap piece of the new flooring as a height gauge and use an oscillating tool to cut door jambs and baseboards.

Worked pretty well for him and went really fast.

Never did it myself, so I cannot speak to how dumb-proof it is or how much skill he possessed doing that.

I have removed all the wall to wall carpeting in my house and installed hardwood flooring in all rooms and the stairs....the room with the fireplace is the last room. I used the multi tool as your co-worker did..undercut door jambs, drywall, baseboards, stair ballusters. Works great, doesn't require much skill and doesn't create a lot of dust compared to an angle grinder. When I did the drywall undercutting I had the multi tool in one hand and the shop vac nozel in the other....same when I used it to scrape the globs of drywall compound off the plywood sub-floor. I'm going to try it on the brick with a diamond blade and see if it works well enough to forgo the angle grinder.

 

[sberry]

Walmart Black and Decker 30$. Anything else is a waste of time and money.

 

[durallymax]

Here's a video showing a tuckpoint setup. If you can rent one I would, looks much easier and cleaner to use.

Scribe the flooring to the brick - cutting brick inside is a messy job!

x2 any masonry work inside is messy, the speed a grinder runs at throws the mess pretty far too. Had to grind down a little bit of concrete for the new door to our shop, what a mess.

4 1/2 heavy duty. I got the metabo online dot remember how much.

$110 for German made on Amazon.

http://www.amazon.com/dp/B001CSEJLA/?tag=atomicindus08-20

The absolute first thing you need to determine is how deep you need to cut. 4 1/2" grinders do not allow for very deep cuts, but if you don't need to go deep then you will be fine.
.

He said 1/2" to 3/4" is the cut depth he would need.

 

[JIMMIEM]

Walmart Black and Decker 30$. Anything else is a waste of time and money.

Do you mean any other angle grinder or any other tool e.g. multi tool?

 

[strutaeng]

Ah, I see what you are trying to do:

I have never seen this tool; it is definitely specialized for the job.

The biggest challenge with an angle grinder is maintaining the tool aligned with the cut line. Angle grinders are difficult to control because most cuts are performed freehand. I would advice to build a spacer or jig for the blade guard to position the blade at just the proper height. Then, it is just a matter of going slow and moving from left to right. Take your time because if the blade gets skewed it could kickback and jump and chew the brick above!

Be careful and wear proper safety equipment (faceshield, dust mask, earing protection, etc.)

You should have a helper with a shop vac like in the video.

Good Luck!

 

[JIMMIEM]

Ah, I see what you are trying to do:

I have never seen this tool; it is definitely specialized for the job.

The biggest challenge with an angle grinder is maintaining the tool aligned with the cut line. Angle grinders are difficult to control because most cuts are performed freehand. I would advice to build a spacer or jig for the blade guard to position the blade at just the proper height. Then, it is just a matter of going slow and moving from left to right. Take your time because if the blade gets skewed it could kickback and jump and chew the brick above!

Be careful and wear proper safety equipment (faceshield, dust mask, earing protection, etc.)

You should have a helper with a shop vac like in the video.

Good Luck!

Thank You. Crain is a top of the line manufacturer of this type of tool. Expensive to buy and can't find a rental. An additional problem is the fact that the concrete pad, that the brick hearth rests on, is almost 1/4" higher than the plywood sub-floor and extends 3 1 /2" inches out from where the brick ends. I'll need to get a dust shroud for an angle grinder to grind down the concrete otherwise I'll have to rabbet the new flooring so it will be able to sit flat on the sub-floor and the raised concrete pad. As you suggest I'll make a platform or jig so that I can keep the angle grinder level when I (eventually) undercut the brick. In case you were wondering, there was wall to wall carpeting in the room and it really wasn't bothered by the concrete being higher than the plywood subfloor.

 

[jzmtl]

Depends on how much clearance you have, may be a lot less messy if you were to drill out rows of holes then chisel out the rest.