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Bolts for power hammer foundation


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Hey guys,

 

I am purchasing a 100lb LG and have been looking over the foundation plans on the site. I'm trying to get a hole cut in my existing concrete slab ahead of time and have the bolts, etc i need for when I go pick it up. The plans show 7/8" bolts something like 3 feet into the ground. Do you guys usually just use some all thread rod or do I need a certain grade bolt? Does it matter? I can't seem to find any 7/8" bolts that are that long. Does anyone have a source for something like that?

 

Thanks!
Cody

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I needed 1 1/2" t headed bolts when I installed my Massey.  I  "forged" them,  I was going to take them to a machine shop to have them thread them but luckily for me there is a place at the end of my block that manufactures bolts and they threaded them for me. 

 

I cannot recommend the Massey set up enough, T bolts with a square shank just below the head.  holes cast in your concrete down to steel plates with a cavity under them.  The steel plates have a rectangular hole in them.  You then drop your bolts into the holes. Put your hammer in place not having to worry about minor misalignment and damaging the threads. Then you pull the bolts up with a 1/4 turn put on your nuts and your done, If you ever break a mounting bolt they can easily be replaced.  

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B7 all thread just a bit smaller than the hole in the frame...or make them 1"

Set the hammer and drill the holes with the hammer in place OR place hammer on cardboard or pattern ply and mark the holes (save pattern for next move).

Drill holes in concrete when crete has set. Rule of thumb is 9x the diameter of the rod...so 1" diam would be 9" deep. Holes are 1/16-1/8 diam larger than the rod.

Blow out the hole with pressurized water from a sprayer. The epoxy will cure under water, but I vacuum out the hole anyway....epoxy will do nothing to hold the rod if the hole is dusty.

 

Place hammer on pad and squirt in two part epoxy..many places have it including fastenal where it comes on one tube and use a normal chalk gun.

Push in allthread. Let cure. overfill the first hole and the next one will be perfect as you know how much not to add.

 

Nut up the system and go to work.

 

I like to bugger up the ends of the thread to go in the holes to get more epoxy purchase as well as drill a hole and pin the nut so it will not turn out with vibration.

 

My 3B is placed like this on 2" of wood  for the frame and it has worked well for 9 years.

 

Ric

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Good Morning,

 

I set the L-shaped 'Dewey-Dag' in the concrete when I poured it. If you want it to wiggle a bit, put some plastic pipe around it where you want it to be free.

 

The only reason not to put the bars in the foundation, is, you may not have the ability to lift the weight over top of the studs. I have the ability to lift heavy things.

 

Neil

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If you are using resin to anchor the bolt most of the advantage of great length in the bolt is lost if the resin is brought right up to the top, the only bit of bolt that can then be elastic is the bit above resin/ground going through the hammer frame.

Provided you use enough to meet the resin manufacturer's pull out specification the lower down the hole the resined area is the better. You are then achieving some of the positional flexibility and strength/spread-strain advantage of the Massey / Alldays and Onions tee headed bolt systems without the hassle of casting in the base plates and tubes.

Incidentally the Alldays Tee bolt design differs from the Massey one described above, by not having the square section to prevent rotation. The base plate has blocks on the underside so you can drop the tee bar down through the slot below the level of the blocks and then rotate 90degrees and lift up to lock the Tee bar between the blocks. Simpler bolt forging and the base plate is arguably also easier to construct.

Having said that both of my 1cwt / 50kg / 112lb air hammers are just bolted to floating base plates or inertia blocks and sit on rubber buffers without any holding down to the ground bolts. The buffers either sit on soft grip mats or are corralled in fixed rings to prevent any walking across the floor.



Alan

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Thanks for all the advice guys! This is very helpful.

 

I was planning on casting these bolts in the concrete to begin with. Is there a reason that most of your are saying to drill holes in the concrete afterwards?

I did it that way because I wanted the bolts and holes to line up when done and wanted the four foot concrete casting to be a simple thing.

 

 

Ric

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Thanks for all the advice guys! This is very helpful.

 

I was planning on casting these bolts in the concrete to begin with. Is there a reason that most of your are saying to drill holes in the concrete afterwards?

 

 

 

I've done it both ways when I worked pouring concrete for a living. Wet set anchors we usually had made up, either by out local concrete material supplier or by a local welder. The supplier usually just threaded heavy rods and then bent the L at the end based on the size and length specified. The ones from the welder occasionally were simply allthread bent, but occasionally were fabed up ones.

 

If you go this route, you'll want a base plate with matching holes drilled in it. We'd usually use 3/4" ply wood or steel. Steel would be used if we needed the plate to set flush and level in the crete. Plywood was used if we didn't care if the nuts stuck out of the crete. We'd position the anchors and install a nut on both sides of the plywood/plate to lock the bolt positions in place. Then the  anchors were either tied to the reinforcing steel or wet set when we poured, depending on the job. Mostly these were done for columns, so we'd mark center and column lines directly on the plywood or steel and use string lines or a transit to locate the bolt locations exactly. I doubt in your case being off a bit will really matter. If you are worried about the bottom nuts, you don't have to sink the template down that deep in the crete. You can always back off the nuts when done, you just have to make sure the threaded part of the rods extend enough to secure what you need.

 

 

 

Epoxy anchors were usually used if we couldn't get an exact location for what ever reason, or if for some reason we had to cut out poured in place anchors due to them being in the wrong place. You need to let the concrete set for at least 3 or 4 days minimum to harden up enough to drill and not crumble unless using high early concrete. As mentioned getting the holes clean is of the highest importance. On one job where we had to epoxy set hundreds of rebar wall bars, I made up a special long blow gun tube out of 1/4" copper pipe soldered to the blow gun tip so we could blow out the holes faster and easier with the compressor. We would vacuum the holes, blow out the holes, scrub them with a dry bottle brush, blow them again and brush them again with a wet bottle brush and shop vac again.

 

Biggest reason we usually didn't use epoxy was time and cost. We could wet set the bolts and level the steel plates and walk away. If we had to use epoxy, there was the added expense of the epoxy, plus the added time to come back to the job ( assuming we did the original pour) and then locate and set anchors. In some cases where we had large numbers of columns to do and they were close together, it was easier to come back and locate all the anchor bolts exactly later rather than have 50 string lines and stakes to locate column lines to dance around with the trucks and wheel barrows.

 

When dealing with existing footings and new bolts, it almost always paid to use epoxy, if the footings were already acceptable.

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The Massey and Alldays T bolts are a very elegant solution, and I remember Forgemaster Phil saying if you do the tubes make sure the tubes are long enough for the broken T bolt to fall in and not interfere with installing the new one, that way you don't have to fish out the broken piece, if you do shear a bolt for some reason.  If you are only gonna do this once, might as well do it up nice;-)

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I just had the foundation pit for my 500 lb bradley dug today and we set the rebar cage in the pit before coming in for supper. In my case I made a template of the base of the hammer and the welded all thread rod into that. In my case each rod is 6 feet long, I have done used the method of drill holes after the hammer is in place an then setting the anchors in expoxy, but both times I did it I hit rebar and didn't get the hole as deep as I wanted and I also had trouble getting all the dust out of the holes. I've the the template method one other time and it really works well if you take time to make sure the all thread is positioned just right

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  • 6 years later...

The following link will give you an idea of what's available and some alternatives. I used L shaped grade 5, cast in place anchors when I built my shop. The templates screwed to the forms, the two in the middle of the walls got rebar braces to keep the templates in place during the pour. The anchors were wired to the rebar so the only way one could move is to lift the footing and slab or break.

I used grade 5 rather than grade 8 for being less brittle, we get hurricane velocity winds too often not to account for them in construction. 

If you use cast in place anchors remember to cover the threads in duct tape after you've greased them good. Set concrete is a bear to clean out of threads.

Frosty The Lucky.

https://duckduckgo.com/?q=cast+in+place+concrete+anchor+bolts&iax=images&ia=images

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When I had my power hammer in the air while moving it, I set it down on a piece of card board. Drew the outline and marked where the mounting holes were and punched them out. Then I forged the J bolts out of 1/2 in round stock and threaded the ends. Poured the concrete, set the template on the concrete and put in the J bolts before it set up. Been holding fine for decades.

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