Which size dynabolts should I use?

Hello, I have to re-attach my fathers metal gate to some brick pylons on either side. However because I have to use dynabolts I'm not sure what is the correct size dyna for the holes on the hinges. I'm not really experienced with using dynas but with the 2 options I have in the photo I've attached I can see how either would work but what one is actually the correct option? I've seen a few threads where people have suggested attaching a peice of wood on the brick first then putting the gate hinges on but that would push each side of the gate into each other and it would not close. Thanks.

Dynabolts are not great for hinges. The dynamic loads loosen them. I’d use a chemical anchor with 10mm gal or stainless rod and washers with nyloc nuts. That is why the timber was recommended.

Thanks for your help Pulse, I'll look nto that too.

Yep I agree a chemical anchor would work well. Will never move.

Go to bunnings and ask for the Ramsett Chemset and get some advice from one of their staff.

We use Chemset when anchoring reo into rock for retaining wall footings and the stuff is amazingly strong.

Thanks Ashington Homes, I think I'll return the dynabolts and get what you guys suggest. Cheers.

Make sure you wear gloves when you use it, the stuff is lethal (think superglue times by 100)

Thanks again, quick Q...if I use say 8mm anchor bolts, should I drill 8mm holes or 10mm? I'm thinking does the hole have to be a bit wider cos your filling it with the chemset and it might need a bit more space inside to surround and affix to the bolt properly. cheers.

yes your hole will need to be bigger then the item you are inserting

Thanks.

Interestingly, if you have an existing hole that is way too big, ie you accidentally drilled a 40mm hole and you want to insert an 8mm bolt, they also have a product that will fill that larger hole for you.

A mate of mine suggested to drill a hole, fill it with liquid nails and then put the bolt in. I did something similar years back.

lol I wonder if that would work, never tried liquid nails in a hole. It's pretty amazing stuff. On a gate though the fixtures are subject to some pretty decent forces as you open and close the gate, so probably wouldnt be the best idea.

You could also plug the hole and use 75mm bugles. Not the most professional option but does work. And then stepping up a notch Ramsett do have a bunch of decent screw anchors, so ask you local bunnings dude

One last question, really appreciate your time and help. Should I use a perforated sieve in the hole as well. So, drill the hole, put the sieve in, put in the chemset in, then the bolt. For extra grip and strenght. It's solid brick.

just drill the hole

Ok thanks.

blow it out too with a bike pump or a straw with safety glasses!

it will cope with some dust but too much will reduced bond strength.

Yep, saw that Pulse, the bike pump is a great idea.

Going to get the anchor bolts and chemset from Bunnings this week. But I came across these hinges from Amazon.com.au (US stock) last night that look interesting. Don't know about what kind of weight they can hold though. Anyone seen something similar availble in Oz? I like the fact that the part that attaches to the gate is adjustable, but again don't know how much weight they can hold.

They look pretty ordinary, go to gatesplus or an Aussie online retailer. Ring them and you’ll get better advice than us.