Thread: Chemical capsule hole okay a bit smaller?

The easiest solution would be to drill out the holes in the footing plates so your masonry bit fits through, stand the frame and drill the anchor holes. If you don't have a big enough steel bit, you could use a round file or something to make the hole a tad bigger

I'd be enlarging the hole in the footing plate, when you insert the bolt it mixes the chemicals in the tube and I'd say a smaller hole wouldn't allow a proper mix and you may end up with an inferior chemical set

If you reduce the hole size to suit the bracket you run the risk of the anchor bolt acting like a plunger, forcing the chemicals to the lower part of the hole. The larger hole allows the chemical to rise the length of the hole for a greater bond surface.

Originally Posted by rustynail

If you reduce the hole size to suit the bracket you run the risk of the anchor bolt acting like a plunger, forcing the chemicals to the lower part of the hole. The larger hole allows the chemical to rise the length of the hole for a greater bond surface.

That makes perfect sense. Never really thought of that. I wonder if 13mm would work however....I could always do a test but if it does not work I need to act fast before the chemical sets.

Also replying to Acco's post above, I tried drilling the plate holes bigger but it's quite hard because the drill bit seems to get stuck on the edge of the existing hole. Because I'm only trying to enlarge the hole 1mm or so the drill bit does not want to work properly.

Originally Posted by hayythere

That makes perfect sense. Never really thought of that. I wonder if 13mm would work however....I could always do a test but if it does not work I need to act fast before the chemical sets.

if you do this all you are really testing is whether the volume of chemical fits in the hole

to test the holding power of a 14mm anchor in a 13mm hole requires equipment not commonly found in the home workshop

My experience of drilling an x-millimeter hole in concrete using a hammer drill is that the hole ends up at least x+1 mm anyway, especially if you pull the bit up and down in the hole a couple of times.

Why don't you make a test hole with the 13mm bit and measure it to confirm size of hole produced?

Hi hayythere,

I'd go with the 13mm bit, drilled to the correct depth. Clean the hole out with your compressor (watch your eyes). Plonk the capsule down the hole and wind the anchor in with your drill.
You might get a negligable amount of chemical forced out of the hole, but your anchor will be well and truly locked in.

Regards,
Geoff.

Thanks for everyones help so far. I just had another thought. I've seen before steel drill bits that are 13.5mm. I might goto my hardware store and see if I can get a 13.5mm masonry bit or a imperial sized bit between 13mm and 14mm. I think 13.5mm would fit through the plate and obviously the closer to 14mm I get the better.

Personally I would consult the shed suppliers and Ramset for their views, Obviously the shed supplier should be supplying appropriately drilled base plates, and Ramset might have prior knowledge of attempts to use undersize holes, and either OK or poopoo the idea.

If they specify a 14mm hole, they could be refering to bit size, accepting that the finished hole would be oversize (say 15mm), or they could be refering to the actual hole diameter.

If you need to open the baseplate holes, maybe try to go to 16mm instead of 14, that way each face of the bit is getting to cut 1 and a bit mm, instead of just a fraction of mm. Either way is a job for low speed on a decent drill press with decent jigging and clamping to secure the plates.

I've just thought of a new plan. After my trip to several hardware stores they only seem to sell masonry bits in 13mm and 14mm and no in between imperial sizes.

I thought I will try grinding the sides of my 14mm masonry bit (the butterfly bit) just a little bit to allow it to fit into the plate. This will only be a fraction of a millimetre smaller than 14mm. If it works I thnik the capsules will be okay, A fraction of a millimetre is nothing really, I hope.

The purpose of the exercise is to get a good charge of chemical up the sides of the hole. An under sized hole makes it difficult for the chemical to rise and an over sized hole has too much void for the given amount of chemical.

Given that the frame has to be errected in stages -- one piece at a time
You don't need to drill all the anchor holes at the one time
Drill them as you need to install each post. Then after marking the hole locations you only need to move one post to drill for the anchors.
Alternatively measure accurately and use a plywood template that matches the hole locations but accomodates your 14mm bit.

A step drill would be the easiest option to open up the holes in the foot plates. Sometimes refered to as a "christmas tree" bit. They are expensive but they work very well in material up to about 3 mm. I would be using the correct size masonry bit. The foot plate holes could be opened up to 16mm without any detrimental effect.

Cheers

Originally Posted by Enfield Guy

A step drill would be the easiest option to open up the holes in the foot plates. Sometimes refered to as a "christmas tree" bit. They are expensive but they work very well in material up to about 3 mm. I would be using the correct size masonry bit. The foot plate holes could be opened up to 16mm without any detrimental effect.

Cheers

Or also called a "Unibit"