Crack Filler for Concrete?

Question

I need stuff like this http://www.blankskateshop.com/FIX-IT-Crack-Filler-p/acficrfi.htm but my skateshop in my town dosnt sell it. Is there any other brand at walmart? or somewhere. I need to fill some cracks at a skatespot. Its Concrete. It would be nice if it would dry kind of fast.

Answer 1

try looking at some of the epoxy grouting mixtures used for tile - if your concrete cracks are not too wide or deep this might do the trick - it sticks like H*ll to anything porous, wears like iron, and cures/dries in about 6-8 hours tops. If the crack goes down more than 1/2" use a bit of foam cord to support the bottom of the grout in the crack (foam cord as is used in insulating gaps around windows during installation into the frame of a house). If the crack is also is more than 1/2" wide you'll likely have to apply a second fill after the first one sets up, this stuff shouldnt be applied more than 1/2" thick per coat, at most. Polyurethane based stuff comes in bags of powder, mix with water as directed, always start with about 10% less water than spec'd for the mix, it's easy to add more but a bugger to take away... adding more powder is definitely NOT the way to adjust a mix! For small cracks, use a pastry bag and nozzle from your local 'dollar store', sure beats messing around with a putty knife trying to get the stuff down far enough into a crack to make a difference! I have used a small amount of acrylic binder ( see a local art supplies store if you have access) in the mix to get it to bond and set up hard as rock - let's say 2 cups of grout mix to 1/2 -2/3 cup water, add and stir until it looks like lumpy muffin mix, sort of dry and not quite smooth - then add 2 ounces of 'Acrylic Artist's Medium' - looks like milky pancake syrup, might also be found at your home center store as 'Acrylic Medium for Stain', etc. Bottom line, - acrylic, water based, syrupy consistency (describing the medium, not your grout mix!) Mix thoroughly, now you have a sticky goop you can force through the pastry bag nozzle. So much for smaller cracks.
For larger pits and holes, spray the cleaned area with water. Apply some of the mixture above to the area, and work it in with a stiff bristle brush (not metal). Add 3 tablespoons of silica sand (it's nicer, but clean bagged 'playground sand' can work) per cup of the mix as used above, if you didnt add the acrylic medium you may need a little less sand, bottom line is its going to be sort of like stale toothpaste - flows, but only just. NOW get the putty knifes out. Force the mixture into the cavities, in 1/2" deep layer max and allow to set/cure, repeat to fill deeper cavities. (you can try to fill deeper but I warn you the dry time sort of doubles every 1/4" you add...) To make this sort of repair last the edges of the hole should be slightly undercut, but as it is easy to whack in a patch undercutting is more work than it may be worth.
True 2 element epoxies are out there, but are not cheap. These are available at home centers but may go for up to 75 a gallon. They are tough, stick to any sort of concrete, cure rapidly (too fast if you get the proprtions wrong or have to fill a large number of holes) , but are muy toxic when mixed and handled, please do wear gloves if you decide on the 'true epoxy' route (the acrylic/polyurethanes are not really 'epoxies' they oxidize rather than polymerize to set up into the final state).
"And now that you're exhausted by all this, have a nap - and dream about mufflers..." (groan...) Regards and Luck, Brett.

Answer 2

Glad I can help. Bondo works great. Make sure the area to be patched is free of all loose material and dust, by either blasting
with water (and completely letting it dry out) or preferrably, compressed air.

You'll get the rigidity that you need for your wheels, as well as the flexibility required for concrete movement.

No offense, Neil, but I am quite familiar with the properties of polyurethane and it will not support the weight of the skater's wheels.

Answer 3

You can use United Products VinylPatch. Dries fast & is rated for heavy traffic ( cars/forklifts ) , you can buy a 40# bag for about $17.

Find a concrete supply house near you like Janell, Goedecke or Enco Materials.

Answer 4

Use polyurethane sealant for concrete and masonry. It is an excellent crack filler and is flexible to allow for some expansion in the concrete.