Little hobby of mine

[John4cam]

I've been getting into precast concrete lately and have alot of things made so far.

I'm most interested in garden themed casts but I'm also doing some others. It's a fun thing to do and alot of these things make great gifts for my relatives, friends ect. It also kills time during these crappy winter months.

Couple cell phone pics of what I've been working on.

[How Much?]

I've been getting into precast concrete lately and have alot of things made so far.

I'm most interested in garden themed casts but I'm also doing some others. It's a fun thing to do and alot of these things make great gifts for my relatives, friends ect. It also kills time during these crappy winter months.

Couple cell phone pics of what I've been working on.

Pretty cool stuff, and good way to pass the time, advertise on CL and make a few bucks!!! My grandmother would buy some of that! She made me take her to a place to get some concrete deer and different crap for her yard,,,,And that stuff isnt cheap, She shell'd out all kinda loot for it

[billyNOTnice]

sweet you need to cast some mustangs to put in my garden

[pRojekt02GT]

sweet you need to cast some mustangs to put in my garden

Those are pretty neat..bet you could make a nice couple bucks of some of those.

[John4cam]

sweet you need to cast some mustangs to put in my garden

Lol.

I'll have to keep an eye out, they actually sell molds that are plaques that have different antique vehicles on them. If I found a mustang it would be bought for sure.

Really, any fast modern car I would buy.

[John4cam]

Those are pretty neat..bet you could make a nice couple bucks of some of those.

Thanks, yeah I've been thinking about hitting a couple flea markets this spring/summer.

[95riosnake]

Pretty nice stuff! I worked at a precast concrete plant for 5 years (senior year in hs through college) and know all about the difficulty in making what you've made. We made several large panels for PNC park (weighed 60,000lbs a piece) all the way down to spindles for railings and window sills. I learned a lot working there about molding, which I have applied to many other things in life, like fiberglass molds and even in my career because I have to engineer the tooling for my designs.

It is a very satisfying thing to do though, I've made several gifts for my mom out of concrete for her to put in her flower beds at their house

[John4cam]

Pretty nice stuff! I worked at a precast concrete plant for 5 years (senior year in hs through college) and know all about the difficulty in making what you've made. We made several large panels for PNC park (weighed 60,000lbs a piece) all the way down to spindles for railings and window sills. I learned a lot working there about molding, which I have applied to many other things in life, like fiberglass molds and even in my career because I have to engineer the tooling for my designs.

It is a very satisfying thing to do though, I've made several gifts for my mom out of concrete for her to put in her flower beds at their house

Thats interesting. I know exactly what panels you're talking about at pnc park.

Do you know how to make molds then? That was on the list for me next. It's amazing how much you learn in a short period of time just diving in and doing it though. The one pic of the white baluster is a part of a railing system I'm molding for my front porch. I like the fact that not too many people have them and it's not cheesy vinyl railing from lowes or home depot.

[95riosnake]

We made the molds out of layered plywood and bendable plywood. For instance, if you wanted to make a curve, you make several rib-like supports and screw the bendable plywood to the supports (looks much like the construction inside the wing of an airplane). Then you make a flange on the top edge to trowel against, and end caps (we called them bulk heads) which you could bolt on and off.. The screw holes were then filled with bondo, along with any other imperfections. The last step was what we called form coat, which is a very thick resin that is brushed on, then sanded smooth after it is cured.

Right before pouring, we sealed the ends with silicone caulking, then wiped the form down with oil (wiped out the excess because it will discolor the surface if left on too thick) and poured it. We used a vibrator that was pushed down into the concrete, which would help it fill all the fine details of the form, and also cause air bubbles to rise to the surface to create a stronger piece. Let the piece cure over night and pull the mold apart. To re-pour, you have to scrape the caulking out, reassemble the form, re-caulk and oil, etc...

We also put in reebar cages and supports for strength, but that isn't as necessary on smaller stuff that doesn't support large amounts of weight.

Also, you've probably noticed your pieces come out smooth and shiny, whereas most precast pieces you see have a sandblasted/rough finish. That is the result of spraying them with a very nasty and toxic acid solution, letting them sit for a few minutes, then power washing it off to neutralize the acid. I doubt you want to get into that stuff lol.

Here's a quick sketch of how we made our molds.

[John4cam]

Nice sketch Dan.

Yeah the molds i'm using right now are abs plastic, and I use either cooking spray or wd-40 for a release agent. The finish is usually very nice and smooth. The wd seems to keep bug holes to a minimum. If I get real into it, i'll probably end up building a vibrating table.