wedge brick

[olddude]

depends on how big your gaps are if your mixing your own as did get one small bag of fine sand use that on your small gaps then use the regular sand on the rest just make sure it's clean no dirt

kinda works like this the cement bonds the sand (rocks ) together
so if you're joint's are big and you have fine sand this will be weaker and might crack
ie more rock's to hold together

but if your rocks (grands of sand ) are so big they can't get in or are to few to get a good bond

hope this helps

[stonylake]

thanks, i think i'll get a bag of #30 silica and see how it works. i got a broken bag of heatstop 50 from the brick yard, but it think i'll use that on the dome after it's done. i was going to go to Lake Michigan and grab a couple of buckets of beach sand, but one of the other builders thought the grain was too big..