Help - Core drill choices

[William McCormick]

Just replying publicly to a couple of messages :
If its a concrete balc and going to be baseplated for what ever reason our procedure is to prior to waterproofing or tiling we will install our rods (always a chemsetted Stainless allthread) we dont use expanding masonary anchors. We then bolt down (finger tight) a "Can" the same shape and size as the base plate we are using. The tiler tiles up to can . When he is done we remove cans and fill between conrete and top of tiles with non shrink grout. When cured we the install balustrading . Yes a few more trips but that is just the price of doing a better job than the rest of the mob. You can avoid all this by coring though.
Same procedure with a composite deck , ie timber joists with compressed sheeting , waterproofing and then tiled.
On bigger jobs the most common reason why we base plate is the engineer not wanting us to cut through his reo .

When I do gates, I cement in and then fill a pipe of a smaller diameter into the ground. I do a rough leveling on it. Then I put the decorative piece over it level it well and fill it with cement. That is tough to loosen or get out. I do that in courtrooms as well for the knee walls that stand in front of the people watching the trial. I core and QuickRok pipe into the floor that I then cover with the wall.

Sincerely,

William McCormick

[William McCormick]

They often pour a huge cube of cement with large diameter studs set into the cement rather deep under those lights. The bases of the light posts are usually castings that have gussets near the bolts so you can get away with that kind of sized plate. But for handrails, you need a large plate. A 1 5/8" O.D. tube or 1 1/4" pipe calls for a 5/8" thick plate five inches in diameter. And if that five-inch plate goes onto a cement walk that has been patched it cracks the patch if you put pressure on the rail, of this I am sure. And even using the Hilti injection epoxy with stainless studs you can loosen the studs by applying the force that falling into the rail would apply. So if you want to use plates they have got to be big and thick.

Compare things you have done in a shop with a three-foot bar and quarter-inch material. The quarter-inch material just gives with a three-foot bar, so does a quarter-inch base plate.

Sincerely,

William McCormick

If you would like more strength you could core in a few 1 5/8" semi leveled pipes and then put the rails over the cored pipes and Pour a little cement into them and pop on the caps.

Sincerely,

William McCormick

[William McCormick]

If it was for my convenience and speed I'd use baseplates every time,
I used baseplates for this Chippendale railing, but only because I wasn't gonna core a 4" square post.


It's so fast to plop the railing down and drill a couple holes and throw some expansion anchors in, but to me, I don't see that as quality at all, I've only done that when necessary.

Fabrication is easier when you're coring, true, and install is way more flexible, you can do a lot with leveling a rail that's cored, with baseplates of u make a small mistake, you're stuck with it.


Sent from my SM-G973U using Tapatalk

Very nice rails. They look really great.

Sincerely,

William McCormick

[winniweld]

My customer is pretty set on the plates and sleeve anchors, and the customer is always right so it’s gonna be plates and anchors! Im confident it will be fine and if not I’ll get paid to core it and make new posts like I wanted to in the first place. Im waiting for a delivery of plates and shoes and post caps that’s been on a truck from LA since 6/30 and is still only in Pennsylvania….

I’m still thinking that I should move up to an SDS max rotary hammer that I can use to core drill for future jobs. I’ve been doing a little research on the inter webs but most of the information seems to link to Amazon so I bet it’s all planted out there to benefit Amazon’s bottom line and not necessarily accurate… I know that William recommended the Eisenbach what other rotary hammers are you folks using with good results? I’d like to keep the cost around 5-600 bucks but my budgets usually go out the window when i start looking seriously.

[wb4rt]

My customer is pretty set on the plates and sleeve anchors, and the customer is always right so it’s gonna be plates and anchors! Im confident it will be fine and if not I’ll get paid to core it and make new posts like I wanted to in the first place. Im waiting for a delivery of plates and shoes and post caps that’s been on a truck from LA since 6/30 and is still only in Pennsylvania….

I’m still thinking that I should move up to an SDS max rotary hammer that I can use to core drill for future jobs. I’ve been doing a little research on the inter webs but most of the information seems to link to Amazon so I bet it’s all planted out there to benefit Amazon’s bottom line and not necessarily accurate… I know that William recommended the Eisenbach what other rotary hammers are you folks using with good results? I’d like to keep the cost around 5-600 bucks but my budgets usually go out the window when i start looking seriously.

As I reported in an earlier post, I tried using my SDS plus drill and adapter with slow but acceptable results. I’m sure SDS Max is more capable but if you would have to buy one I strongly recommend you purchase a core drill instead.

My Eibenstock is awesome but I’m sure there are other good brands. If your budget is $600, I would make the additional $300+ investment for the assurance. It is German made and very well made.

[tapwelder]

My customer is pretty set on the plates and sleeve anchors, and the customer is always right so it’s gonna be plates and anchors! Im confident it will be fine and if not I’ll get paid to core it and make new posts like I wanted to in the first place. Im waiting for a delivery of plates and shoes and post caps that’s been on a truck from LA since 6/30 and is still only in Pennsylvania….

I’m still thinking that I should move up to an SDS max rotary hammer that I can use to core drill for future jobs. I’ve been doing a little research on the inter webs but most of the information seems to link to Amazon so I bet it’s all planted out there to benefit Amazon’s bottom line and not necessarily accurate… I know that William recommended the Eisenbach what other rotary hammers are you folks using with good results? I’d like to keep the cost around 5-600 bucks but my budgets usually go out the window when i start looking seriously.

Seems like you are confusing rotary hammer vs core drill. I would not get a percussive drill for serious core drilling of railing.

How will you manage the plates and shoes? Will you weld them on site?

[winniweld]

Seems like you are confusing rotary hammer vs core drill. I would not get a percussive drill for serious core drilling of railing.

How will you manage the plates and shoes? Will you weld them on site?

So I guess I’m mistaken thinking that a dedicated core drill is a hammer type drill. I was thinking to keep my cheap sds drill for drilling anchor bolts and use a sds max with a core bit for coring when necessary. Are coring drills rotary only? I was leaning towards the SDS max as I’m always looking for versatility in my tools so I can get multiple uses from each. I’ve never needed to do coring in the past as all my railing work has been residential work and I’ve been able to use anchor plates with very good results. I guess I need to do some research on core drills.

As far as the plates my plan ( if they ever get here……) is to assemble the posts and paint them in the shop then install on site. Then I’ll mount the rails on the posts and prime/paint the railings on-site.

[wb4rt]

Core drills are rotary only. You do not want hammer/impact on wet core drill bits. They cut with the diamond edge only. Hammering will dull your bit and possibly crack/crumble your surface- especially brick or pavers. The core cuts a smooth hole.

Unlike a SDS drill, a core drill has a hose attachment and the water flows inside the bit to keep it cool. With a SDS you will need someone to keep the bit wet with a pump up sprayers or other method. Read earlier posts in this thread.

There are dry bits and certainly impact type hole bits but I recommend the wet core bits - available on Amazon and others. My 2” bit was around $40.

Core drills can be handheld or mounted on a rig. Most have 2 speeds and a clutch that releases if it binds. They will cut rebar.

I suggest you do more research and ask questions here before you invest several hundred dollars. It sounds like you are growing in the handrail business so it makes sense to me to make the investment in the equipment. The best return on my investments have come from investing in myself.

[winniweld]

I’m looking at dedicated core drills this morning and I’m finding some good used options out there. I’m looking at a several on various online sales platforms (FB , CL, EBay) and I’ve got a few questions, are the bits standardized across the manufacturers? I see 1-1/4 - 7 called out on some, others make no mention of the threads on the drill arbor. I’d hate to buy into a drill that only takes cutters from a certain manufacturer, you’d be screwed if they went out of business or jacked up the cost. Also how important is the drill stand? The stands are pricey, I’d rather start with a handheld that can be mounted on a stand later if usage warrants it. What about the bases on the stand, some bolt down, others use vacuum, is it as big a pain as it seems to drill an anchor bolt for each core you have to drill only to then fill it in when you are done.

[Brett]

Please note all my comments are from an Australian experience ...

I’m looking at dedicated core drills this morning and I’m finding some good used options out there. I’m looking at a several on various online sales platforms (FB , CL, EBay) and I’ve got a few questions, are the bits standardized across the manufacturers? I see 1-1/4 - 7 called out on some, others make no mention of the threads on the drill arbor. I’d hate to buy into a drill that only takes cutters from a certain manufacturer, you’d be screwed if they went out of business or jacked up the cost.

The most common thread is 1 1/4 UNC , there are also Hilti specific , M20 and 1" .
Pretty much all the top line drills use 1 1/4 .
The M20 and 1" bits are more common in the cheaper bits and drills.
They all work.
There are adaptors available , but its been my experience that they add slop and wobble . This speeds up bit wear of bit and cannot be good for the drill. Avoid if you can , but sometimes you can come across a red hot deal on bits .
Go the 1 1/4 .

Also how important is the drill stand? The stands are pricey, I’d rather start with a handheld that can be mounted on a stand later if usage warrants it. What about the bases on the stand, some bolt down, others use vacuum, is it as big a pain as it seems to drill an anchor bolt for each core you have to drill only to then fill it in when you are done.

For balustrading , they are not very important , and IMO not worth the hassle.
There are plenty after market stands that have a universal collet for your drill . Stands are mainly for big diameter holes or specialty drilling ie horozontal or inclined. Get a good drill , drill by hand , get a stand if you need one ... you probobly wont need one .

[winniweld]

I was able to purchase a Weka DK 13 off of eBay for 300 beans. I got just the drill and the case, none of the other accessories are there, I need to make or purchase a side handle and maybe the adapter for 5/8-11 . They want 150 clams for the 2 parts that make the side handle , I have a lathe and mill so I’m gonna see what I can whittle up before I buy one from the OEM. I’m also going to need some cutters for this, can I get a little input on those? How much larger than the post should the hole be? There seems to be a lot of these out there and prices are all over the place, who are the reputable manufacturers and where is a good source for them?

[wb4rt]

I was able to purchase a Weka DK 13 off of eBay for 300 beans. I got just the drill and the case, none of the other accessories are there, I need to make or purchase a side handle and maybe the adapter for 5/8-11 . They want 150 clams for the 2 parts that make the side handle , I have a lathe and mill so I’m gonna see what I can whittle up before I buy one from the OEM. I’m also going to need some cutters for this, can I get a little input on those? How much larger than the post should the hole be? There seems to be a lot of these out there and prices are all over the place, who are the reputable manufacturers and where is a good source for them?

I use a 2” core for 1” posts. That gives enough room to position the post a little and enough capacity for the Quik-Rok. Most bits big enough for railing will use the 1 1/4-7. I bought my bit from Bluerock on Amazon. It seems well made.

You will need a side handle. Also check your manual. I saw the Weka has 3 speeds. Select the speed based on the size bit and if handheld. My drill has 2 speeds and requires the higher speed for handheld.

[Brett]

I was able to purchase a Weka DK 13 off of eBay for 300 beans. I got just the drill and the case, none of the other accessories are there, I need to make or purchase a side handle and maybe the adapter for 5/8-11 . They want 150 clams for the 2 parts that make the side handle , I have a lathe and mill so I’m gonna see what I can whittle up before I buy one from the OEM.

The last one we bought was a DK 16 240v over here , I think our older ones were 13s or 14s . The collet size on the handles are the same diameter for the old and new drills .

and maybe the adapter for 5/8-11 . They want 150 clams for the 2 parts that make the side handle , I have a lathe and mill so I’m gonna see what I can whittle up before I buy one from the OEM.

Over here at least I have never seen a Weka that was not a 1 1/4 UNC .....

I’m also going to need some cutters for this, can I get a little input on those? How much larger than the post should the hole be? There seems to be a lot of these out there and prices are all over the place, who are the reputable manufacturers and where is a good source for them?

Good quality fluid grout does not need much between wall of hole and wall of post.
Basically drill the smallest hole you can and get encapsulation . The thicker the grout the greater the gap.
The other limiting factor is your ability to drill plumb , but that comes , also the smaller the bit the easier and quicker the drilling , by a good margin .

The holes we do are :
38mm dia post = 50mm bit, sometimes a 44mm
50mm dia post = 57mm bit
25x25 sq = 44mm bit
40x40 sq = 63mm bit
45x30 post (our system) =57mm bit sometimes a 63mm bit
50x50 sq = 75mm bit

[tapwelder]

My weka 12 is 1 1/4. The adapter is easy enough to locate. Toolsdirect.com. I have one from them.

My wet core saws fit directly. I purchased a 1.5 inch dry saw a couple weeks and it needed an adapter...which I had.

Next. Dust and water management. It is actually a big deal. Not considering legal requirements, it sure makes cleanup easier and productivity.

[Brett]

Hey Tapwelder
Hope you and yours are well.
Brett

[tapwelder]

Bought this the other day. Thought it was worth 75 dollars. The drill has rotary hammer mode. Cannot see using the drill. Figured I could sell the drill with adapter to make the saw a good deal.

Not something i would like cord dill with. Looks identical to my crazy black and decker. It will twist an arm good.

[wb4rt]

This week install:

[tapwelder]

here is the drill I purchased. Probably will never use it as a core drill.

[tapwelder]

Rail looks good. How was it drilling the limestone cap. An instance where core has benefit over percussion.

How do you clean up or maintain clean area.

[wb4rt]

Rail looks good. How was it drilling the limestone cap. An instance where core has benefit over percussion.

How do you clean up or maintain clean area.

Drilling the stone was no problem at all, very similar to concrete. In fact I think it was actually man made stone looked very real.

As far as clean up I’m constantly wiping with a wet rag and small brush. I also use a shop vac to clean up and suck up excess water in the area and in the holes. That’s important to keep it clean so the Quik-Rock doesn’t dry and create a mess.

This latest job was on new porch and steps and I think the mason left such mess my drops would never be noticed.

[geezer]

Hey Burt, sure some nice lambs tongue, you have had plenty practice. And they all look good.

Been kinda out of commission last year, elderly parent required on site support as they transitioned to skilled dementia facility, 600 miles from here.

Will post pics of my handrails around deck. Been painting myself, powder coater increased est over double. Since we will probably leave here next couple years or so, my paint job will have to do. More later, nice work

[wb4rt]

No core drill involved, but thought I would post a picture of my latest little project.

[wb4rt]

On a related topic, I have a job to replace 8 old handrails with new. The design will be similar but a little more up-to-date.

They are only 2’ long with 2 at each of 3 doors and 1 at each end of the building. Old rails have 1” square posts cored into the concrete steps. New posts are 1”x1 1/2” tube.




Questions I need help with:

1. Is 2 1/2” core drill the right size for 1”x1 1/2” post?

2. Can I just cut old posts off then core drill with larger bit around the old hole/post? Do I need to leave 4-5” of old post to help pull it up?

3. If I need to adjust the hole location slightly different from old hole, will core drill cut down through old post?

4. What else do I need to know/ think about?

[tapwelder]

If you think you might change location slightly, then I would just core drill around the stub. I would use a smaller core saw or same size as existing hole. I would use larger saw, if I know where I was landing with the new rail and original hole was cut out. I have cut through reba, but you can remove those posts.

You can leave the post long and chisel the grout. It is surprisingly difficult to remove them but will work. Assuming there not set in poured lead…

[Brett]

Questions I need help with:

1. Is 2 1/2” core drill the right size for 1”x1 1/2” post?
Sure 63mm is fine even a 57mm will do.
Size of core hole is a balance between keeping it small as possible to speed drilling , not be too sloppy to wedge up and plumb , not interfer with substrate , but at same time not be too small so that the plumbness of your drilling becomes too critical.
What size bits you own or have on site usually has the most say in the matter .

2. Can I just cut old posts off then core drill with larger bit around the old hole/post? Do I need to leave 4-5” of old post to help pull it up?
That is just what we do . Cut off existing so it leaves a few inches abve concrete. Slip core bit over and drill for 3"-4" . Remove drill , wriggle slug and to will snap off and pull out . The smaller the drill bit the easier the drilling . You cannot leave old slug in concrete .


3. If I need to adjust the hole location slightly different from old hole, will core drill cut down through old post?
Remove old slug...it should not be there anyway , then core to suit new leg centres.



4. What else do I need to know/ think about?
If you can , and it looks right . Make new balustrading the same leg centres as old ones . We do when ever possible . Halve the drilling .