Tuesday, April 10, 2012

Plasma Scooter, Clamps, Umbrella And A Chair Leg

Fixing a whole bunch of things:

1. Nate broke his plasma scooter
2. Nate broke a chair leg
3. The wind broke the sun screen umbrella
4. I broke two clamps
5. I accidentally melted a clamp during aluminum pouring

1. Fiberglass is my friend
2. Polyurethane glue is my friend
3-5. The foundry DOES have a purpose, MELANIE! :)

Plasma Scooter (aka Nate's "Zoomer")
Lining the underside with fiberglass mesh and resin

Nate also managed to break the support arm so the plasma scooter doesn't tip over when steering hard left or right so the fiberglass mesh and resin got thoroughly applied
Another view of the fixed support leg

This is what it looked like from the outside once it was fixed. I think it's acceptable. Not pretty, but acceptable and Nate doesn't care, as long as he can zoom around with his "zoomer"
Chair Leg

Yep, Nate managed to break another leg! At least it wasn't his own this time. This was an easy fix: Apply some polyurethane glue and put it in the vise for an hour and we're good as new
And, because it is all hidden underneath the chair, nobody will ever know that it was fixed

During the molten aluminum pour for another project, some of the aluminum spilled over onto my clamp and because the bracket was also aluminum it melted it completely

I took a good clamp to make an imprint, then used the original screwy handle thing (you can see how the paint was burned during the "accident") as a core around the new part. I also used a custom cut piece of metal as a core for where the actual clamp goes afterwards

Here's what it looked like when it came out. The left vertical column is the sprue and the right one is the riser

After hammering out the metal core, cleaning up the fins/edges and loosening up the screwy handle I put it on the clamp that it originally came off. I only saved about 5 bucks, but it was worth gaining the experience on how to do it

More Clamps
About a year ago I broke the handles off of two clamps because I was a bit too forceful. I kept them just in case any of the others broke so that I could use these parts to fix the others, but then I thought why not make new handles out of aluminum. In the above picture you can see the triangular part that tightens the clamp that used to be connected to the handle that broke off
I took off the handles of the other two clamps that I had managed NOT to break yet and used them to create a mold for the replicates

Here they are in the drag to make one half of the mold cavity

After they cooled down enough to take out of the flasks

After they were broken off the feeder but still with all the fins and sharp edges on them

After they were cleaned out and drilled for the metal pin

Putting them on the broken clamp

Both clamps fixed. They were each about $20 bucks so it was worth doing it and they most certainly won't ever break again!

Patio Umbrella Pivot Part
We bought a swingable patio shade umbrella but during a very windy day it actually snapped right off. Since this was an injection molding created part it couldn't be glued or plastic welded so I put it aside to make a duplicate out of aluminum. However, because the injection molding process used three movable molds I had to improvise somehow to make the ribs at the bottom

First I had to drill a 1" hole at the bottom of the part and fit a piece of dowel into it. This dowel was then mounted on a piece of wood
I bent a piece of flashing around the dowel to allow enough room to make a negative imprint of the ribs

Here is the old (broken) part and the form for making the ribs

I put the original part over the dowel and filled the space with reo-flex two component polyurethane rubber and let it cure for 24 hours

This is what it looked like after I removed the original broken part

Now I could fill up the new cavity that the old part left with another batch of rubber and let it cure for another 24 hours

After I removed the created rubber replica of the ribs, I cut the original ribs off, stuck a dowel into the hole and put the rubber replica onto the dowel. I also cut the original part in half with the band saw so that I could have my split pattern for making the mold. The reason I created the rubber ribs was so that once I pulled the hard part out of the sand I could bend the rubber ribs inwards and gently pull them straight out without damaging the impressions these rubber ribs left in the sand

After the cast was pulled out of the flask and cleaned up

Add a little bit of paint

And there it is. Now, instead of throwing out a completely useless umbrella we can either use it again or sell it for $50 bucks. And, this time the part will certainly never break again
Scissors, grinder, drill press, metal file, foundry, vise, band saw

Green sand, aluminum, polyurethane glue, dowel, fiberglass, 2-componenet reo-flex polyurethane (shore hardness: A60)





Sunday, April 1, 2012

An Oldie But A Goodie: Concrete Driveway

To build a concrete driveway with a rock texture and various shades of color

This is a re-post from my facebook album "Stencilled Concrete Driveway" that I wanted to add to my blogging repertoire: Ok, so this is another crazy project/challenge: i want to "build" my own concrete driveway but who wants a boring grey square block of concrete in front of their house? so how about adding some color, some texture and some tile pattern? well, there just happens to be something called stamped concrete, but the skill level for that is beyond what i dare to attempt at this time so i did some research and found another technique called stencilled concrete. basically you lay a pattern of cardboard (called a stencil) on the freshly poured concrete, throw some color on top which will cover every place the stencil is NOT, then roll a texture roller over the whole thing to create a real rock look (not just the smooth boring flat concrete) and voila! your own textured, colored and stencilled driveway that looks like custom brick or tile or whatever pattern the stencil is.
the first step i had to take was finding a 2ft x 2ft rock in a sandstone query that had a pleasant texture. once i found that rock i proceeded to create a silicone mold of the rock. normally you'd use a two component urethane rubber but since i hadn't ordered it yet i wanted to proceed and used 10 tubes of silicone instead. i didn't realize that i bought the white stuff which left some marks on the actual rock. i kinda wish i had paid attention and gotten the clear silicone but it worked anyways. in retrospect i would have probably waited until i got the urethane rubber instead but since i've never done this it was a lesson learned for the next time. Note:
I'll describe the process below with each picture, but the basic process goes like this:

1. Take a mold of a rock in a query
2. Use that mold to create a polyurethane concrete roller
3. Compact the sub-base of the driveway
4. Put up forms to hold the concrete
5. Build in a sprinkler park for my son
6. Place reinforcing iron mesh in the driveway
7. Place the concrete
8. Smooth out the top, throw on coloring "shake-on"
9. Throw on release powder
10. Roller the texture into the concrete
11. Cut expansion joints
12. Coat the driveway with a curing/sealing agent


Silicone mold of rock from Audubon query
once i lifted the silicone mold off the rock (oh yeah, i used a lubricant that contains silicone before i put the actual silicone on the rock to make it come off easier) i noticed that there were some spots that were just flat and boring so what i ended up doing once i got the urethane rubber was to create a little mini mold of a more interesting area of the original mold as can be seen in this picture
once the rubber cured (16hrs) i lifted it off and got this
then i used silicone to "glue" the little mini molds on top of the larger mold where the boring spots were. in order to see the actual texture better i just used some black spray paint over the whole thing so you can see where i lifted off the mini molds (white) and where i glued them on (yellowish)
now i had to create a core pipe, slightly larger (about 1/2 inch) than what was gonna be the final steel core. i used my router to cut out circles out of mdf and wrapped those circles with aluminum flashing
then i wrapped the silicone mold around the aluminum pipe with the textured side toward the inside
another view of the silicone mold wrapped and taped around the temporary (slightly larger) core
and another one
i attached a strip of plexi glass to the base of the router, measured 3 and 1/8" from the router bit, drilled a hole through the plexi glass, attached it to the mdf and used that as a make-shift "compass" to cut out a perfect circle
the underside of the piece of mdf
next step: create another pipe that goes on the outside of the silicone mold that will hold the mold in place for pouring the final urethane...it'll make sense later
here you see from the inside: 1. temporary larger core, 2. silicone mold with texture facing inward, 3. outside pipe that holds the silicone mold, 4. outside mdf circles that holds the flashing in place
here's the outermost structure that will hold the silicone mold so i can pour the rubber to create my final texture roller
outside structure with the final inside metal core (5 and 5/8" diameter steel pipe with 3/8" thick walls)
the whole thing assembled with the temporary core still in place
from the top
using silicone to glue the ouside pipe to the mdf structure
another view
and another one with the steel core sitting beside it
i had to weld some 3/16" steel to the steel core to enable me to attach the final roller to a handle so that i can roll it over the soft concrete to imprint the texture
this is after i removed the temporary inside core to reveal the texture of the silicone mold. i had to use more silicone to create a seamless seam where the wrapped around silicone mold joined to itself.
another view where you can see the texture of the silicone mold
i had to place a light behind the pipe so i could look through and smooth out the seam
just as a test i placed the final metal roller core inside of the silicone mold
and a close up
i used a piece of mdf to hold the steel core perfectly in place to have an even gap between the core and the silicone mold where i could then pour in the urethane rubber
sealing up all the edges so that the urethane rubber doesn't leak out
another close up
another view of the inside of the silicone mold with the piece of wood attached to the end where the steel core will be screwed to
another view
here's after the urethane was poured to fill in the gap between the steel core and the silicone mold. except for the problem was that once i mixed the two components of the urethane rubber together i only had about 15-20 minutes to fill in the gap and i found out that the viscosity was similar to liquid honey or corn syrup so it wouldn't really flow well into the gap. what i ended up having to do was taking a large ziplock bag, cut a corner off and shove it down into the 1/4" gap, then fill up the zip lock bag with urethane rubber and squeeze it into the gap kinda like icing sugar on a cake. what a mess this was and the rubber was so sticky, i still have splotches on my arms now 4 days later...
a close up of the pour
here's what the final roller looks like. again, to be able to see the texture a bit better i just spray painted it black. the color will flake off once i start using it but it was worth it to see the final result
another view
and another one
and the last one of the roller
after the roller was created i figured i'll make another mold for the areas of the driveway that i cannot access with the roller so i mixed up some more rubber and poured it on the same silicone mold i used to create the roller. it turned out quite nice i must say
another view of the second mold
here's the finished texture roller. 22.5" wide and about 6" diameter. it probably weighs aout 40lbs plus another 10-15 with the handle
a closer look
i ended up cutting a little groove in the end of the "axle" and used a tension clip to hold it in place
as a little test sample I used a piece of osb (40" x 32") and divided it with 3" flashing bent to create a bit of a curvy edge to it so later when splitting it up it looks a bit more decorative
Here's the freshly poured concrete. it took 4 bags of "simply add water" cement mix, 260lbs of it in total
here's after the color hardener was applied. i did mostly slate grey and added some brown and some reddish
this is the antiquing release powder which prevents the texture roller from sticking to the concrete. it also gives a variation of color where the indentations of the roller press into the fresh concrete
this is what it looked like after the concrete was washed, broken apart and coated with a sealer. the driveway will not have the cracks in it but for the front of the door i found it looks a bit nicer
here's a close up
and another one
and another one. notice the darker spots are where the texture roller pressed the release powder into the fresh concrete
compacting the driveway with this 2000lbs diesel plate compactor
nathaniel inspecting the plumbing after all the sprinkler pipes were set in place and "concreted" down. the other "splats" are to put some weight on the buried 1/2" pex pipe to prevent them from pulling out of the ground
here's the composition of the sprinklers: 3/8" stainless steel threaded rod slotted with the angle grinder for easy placement/removal. This piece goes inside of a drilled out and threaded brass cap (pex). The red stuff is wax which i tried to use to cover it all up so it won't get dirty with the concrete, but i ended up using regular vaseline because the wax fell off
27 nozzles with a stainless steel solid core and in the spring i can take out those cores and replace them with ones that have a 1/16" hole in them (that's where the water will then spray out)
placing the wire mesh for structural stability
close-up of the 6-jet circle
the manifold which can be hooked up to my cold/hot water taps. 1 circuit for the 6-jet circle, 2 circuit for the two 6-jet straight lines and 1 circuit for the 9-jet cross
finished with the preparations, ready for the concrete
10.5 cubic meter of 35MPA (that's the strength of the concrete)
placing and screeding. i've had my brother in law shawn, my neighbor marty and a friend from church, josh help out with the dirty work
half-way through we realized that the concrete was setting faster than planned so i had to start coloring it while the boys finished pouring and screeding it
here's the dark gray color hardener
and some reddish and tan accent colors
here's the brown and red powder i used to give the gray/black some color variation
the boys hard at work
once all the color was worked in we broadcast antiquing release poweder which would prevent the texture roller from sticking to the somewhat wet concrete
here's shawn helping me with rolling the texture into the concrete
after it was all done for the night
yes, it was a dirty job
in the morning i brushed the excess release powder and snapped some chalk lines for the concrete saw
cutting the control joints so that when the concrete cracks (yes, concrete will always crack) it will crack underneath the cuts where it is already weakened. I placed a 5" slab and cut about 1.5 inches into the slab
after pressure washing it
here's the 4x8 sheet of plywood onto which i built the forms to create the patio blocks for the front entry
the finished and sealed driveway. it rained today so you can see the little puddles, but the color is what it is during a normal non-rainy day. i think it's beautiful.
here's the form i used to create the patio block stones for the front entry way
here's the front entry way with the patio blocks
another shot of the front entry
and a close up of one of the patio stones with Joshua 24:15 in Hebrew letters
and here's a close up of the 9-jet "x" which will be the sprinkler "park" next summer
here's a closer look at the color variation
and another closer look
a view from across the street. all i'm gonna have to do now is the landscaping and re-paint the side walk; it got kinda dirty too. HUGE thanks to Shawn, Marty and Josh!!! Couldn't have done it without their help! And a special thanks goes to my beautiful wife who put up with me being stressed out for the last couple of weeks and particularly the day of pouring the concrete. She's the best!
hmmm...i wonder what that big fluorescent tape across the side walk means...
well, i don't know, maybe i'll have to go walk on it to find out
how pretty it looks...
yes, and then i think i'll walk back and forth on the beautiful black driveway with my white paint covered boots
a closer look at the home-made patio stones that lead to the side door
the concrete blocks that lead to the side door are anywhere from as large as my hand to platters about 2 by 2 feet (and very heavy). in total the walk way is a bit more than 4 feet wide and 16 feet long
Too many to list, but here's a few: saw, hammer, sledge hammer, 2000lbs rented diesel compactor, bolt cutters, knife, pex crimper, drill, concrete roller, brush, sprayer, rented diamond blade concrete saw for expansion joints, rented magnesium concrete float, other concrete tools, rake, pick axe and many, many more

2 gallons of polyurethane reo-flex (shore 60A) for roller, 2' of well casing for roller core, 24' of 1"x1" square steel tubing for roller handle, 11m3 of concrete, 1 gal of decra seal, silica sand, concrete colorant, cement for dry shake-on material, rebar, wire mesh, 1/2" pex pipe for sprinklers, brass caps for sprinkler nozzles, pipes for 4-circuit sprinkler manifold,


10 for research, 15 for concrete roller, 5 for dry shake-on concrete colorant, 15 for sprinkler set up, 10 for base prep (plus 5hrs paid for an excavator), 5 for actual pouring (plus 4 hours for each of the 4 helpers), 5 for cutting expansion joints, clean up and sealing:

Grand total of approximately 65 hours (not including 25hrs of other people's time that helped out)

$6,000 to $10,000

Love it!