My son is writing an Eagle project to place decorative cinder blocks around posts supporting a scoreboard. Since we don't know anyone who has experience using mortar for building these, a friend told me he used adhesive glue for concrete/masonry and that it worked very well. The blocks will not be supporting anything other than themselves, and will not be retaining any dirt or ground. They will stack up approx. 9' in height. Does anyone know if a heavy duty glue made for masonry will hold these blocks together for an indefinite time instead of using mortar? They will sit on a deep, flat foundation, so there should not be any movement at the base, nor will they be subjected to anything other than the natural elements of mother nature. Will glue work? Thanks!

What part of the country do you live? Mother Nature can raise a house by freezing the ground so if your area will freeze the adhesive will be short lived. How deep is your deep foundation?

I live in Atlanta area. I anticipate the foundation to be at least 6 inches deep

Let me be more specific, is there a frost line in your area?

No, there is not

I stand corrected, it is 6"

I believe there is a cement patching material that can be purchased in tubes like caulking but that would make the project unnecessarily expensive and probably unnecessarily difficult. The weight of the blocks would probably cause any type of glue, such as Liquid Nails to squeeze out.

Morter mix is sand, cement and lime. The sand is the bulk, the cement is the glue and the lime makes the mix plastic like while wet. Sort of makes the sand stick together while you work with it.

Suggest that you purchase a few cinder blocks, a bag of sand, a small bag of lime and a mason's trowel.

Practice laying blocks. Build a wall.

Mix 3 parts sand and 2 parts lime in wheel barrow adding enough water to make a stiff tooth paste like mix. Wet enough to be soft and stiff enough to support the block.

Scoop out some mix using the side of the trowel. Transfer to top of block by scraping off the trowel. Lay a bed of mortar about 1" wide and 1/2 thick on the top edge of the block.
To put mortar on the ends of the block, stand the block on end and "butter" the end buy putting a bed on each edge. Use the corner of the block to scrape the mortar off the trowel. That should put enough pressure on the mix to make it stick to the block. Lift block and set on the previous block pushing the end toward the previous block in that course. Use a level to keep blocks straight, plumb and level.

When you are through or tired, take a break. Next day you can knock it all down, scoop up mix, rewet it and start again.

While I was waiting for the response, I did some research and found a product called Mason Glue. It is approved for use by building codes in Florida and withstood a test of up to 360psi before it broke- but the glue did not break, the actual block did first! Doing this project with young men instead of adults (which is what is required), and knowing none of them have ever done mortar, I think we will go with the glue which will make this project go MUCH faster, and leave little room for error with the right mixture, timing, etc.
Thanks to all for responding to this!

Mortor isn't so bad. Did a couple of rows of bricks on a chimney once.
You put it on angled and push the mortor out.

There is the trowell and the pointing tool. You'll probably need the pointing tool with the glue. That makes the indented seam.

For the walls, you'll need a mason line(basically string) and a level. A level that hangs on a string works. So would a laser level. This keeps your courses (layers) at the same level.

I found this reference online for blocks and adhesives Cinder & Concrete Block Corporation : Cockeysville : Baltimore : Maryland

Remember the blocks are typically hollow, so you will need some a size 1/2 the size of the main block, so that the bricks interleave. Note that there are some with rounded corners. This might make your wall a bit more professional.

I would go with the glue, that you researched. Mortar is not made to stick blocks together. It was designed to fill gaps between irregular blocks made by hand or irregular stones. It became tradition to see a well pointed wall.

Twenty or more years ago a method was developed to lay up dry blocks and stucco both sides with a fiberglass reinforced cement. The strength of this wall is far higher than a mortared wall. Little experience is needed to lay up this type of wall. Quick-Crete makes a product for this. Tradition can be a powerful drag on new development.