Hi. A few tips from a construction worker. Water to cement ratio is SUPER important for concrete strength. The perfect ratio is 0,38 by mass. For every kg of concrete use 0,38 kg of water. It is easier to pre mix water and cement in a separate container and add it to aggregate. For crack resistance you can add fiberglass. You should be able to buy it easily in your local store with buildings material and it is not that expensive. However the fiberglass makes the mixture thicker. In order to combat that you can add dishwasher liquid. Yes the liquid you use to wash dishes. But no more than 1ml for every kg of cement. In order to remove air bubbles you can use cheap concrete drill. Instead of drill bit put piece of soft wood and start "drilling" into the mold. Concrete drill not only rotate the bit but also provide hitting force. Also use some clamps instead of zipties. Clamps will provide more holding force and hopefully prevent molds from moving apart. After 48h take it out of the mold and water the ball severely for another 4-5 days (3-4 times a day). Let it dry for a week. Put some deep penetrating primer on it. Concrete reaches full strength after 28 days.
Very cool. I've got molds on the way to make some. Wondering about an idea of drilling holes through the mold , which ever way, criss cross or whatever, then small rebar through the mold for added durability. I've done a similar technique with other home made weights about a decade ago and I still have and use these weights to this day. Dropping them on gravel constantly they've only started to deteriorate a bit in the last couple years finally.
I wonder if you have tried the duct tape over the seam on the inside of the mold? I would also think that modeling clay, oil-based clay or good clay from the earth, make into a long thin "snake" could be pressed onto/into the seam on the inside. I would tape the outside, as you have done, too.
Hi. A few tips from a construction worker. Water to cement ratio is SUPER important for concrete strength. The perfect ratio is 0,38 by mass. For every kg of concrete use 0,38 kg of water. It is easier to pre mix water and cement in a separate container and add it to aggregate. For crack resistance you can add fiberglass. You should be able to buy it easily in your local store with buildings material and it is not that expensive. However the fiberglass makes the mixture thicker. In order to combat that you can add dishwasher liquid. Yes the liquid you use to wash dishes. But no more than 1ml for every kg of cement. In order to remove air bubbles you can use cheap concrete drill. Instead of drill bit put piece of soft wood and start "drilling" into the mold. Concrete drill not only rotate the bit but also provide hitting force. Also use some clamps instead of zipties. Clamps will provide more holding force and hopefully prevent molds from moving apart. After 48h take it out of the mold and water the ball severely for another 4-5 days (3-4 times a day). Let it dry for a week. Put some deep penetrating primer on it. Concrete reaches full strength after 28 days.
Very cool. I've got molds on the way to make some. Wondering about an idea of drilling holes through the mold , which ever way, criss cross or whatever, then small rebar through the mold for added durability. I've done a similar technique with other home made weights about a decade ago and I still have and use these weights to this day. Dropping them on gravel constantly they've only started to deteriorate a bit in the last couple years finally.
Enjoy watching your videos Martin... ingenious! Subbed.
Thanks ;)
I wonder if you have tried the duct tape over the seam on the inside of the mold? I would also think that modeling clay, oil-based clay or good clay from the earth, make into a long thin "snake" could be pressed onto/into the seam on the inside. I would tape the outside, as you have done, too.
Nice collection of stones you got. I only have one and it's too heavy for me haha
Thanks. Yeah remember seeing your video with it, looks very heavy.
Prøv næste gang med sådan en massage pistol, så får du de helt små lufthuller væk også ^^
hvordan er du sikrede vægten er den du vil have?