Casting Concrete Window Sills
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- Опубликовано: 7 июл 2024
- Not a normal day in the shop. Follow along as I try my hand at casting concrete window sills. Plenty of missteps, but lots more learning! So far the work output is better than I expected.
James, you ARE one lucky Dad 😊. Thanks for sharing 👍👍😎👍👍
James,
Good to see the apprentices helping...
Take care
Paul,,
Thanks for a new video!!!!! Greetings from Gretna, La.!!!!!!!!!
I'm a New Orleans native myself, old jefferson
Hello Mr Killroy, nice to see/hear from you. Stay safe, stay healthy. . I still get Commits on my shirt when wear it! Mostly from the younger crowd, asking what is kilroy? Ha Ha
two things I thought of while watching...one is putting the bucket on a small square of plywood so you can stand on the plywood corners. We just screwed through the plastic with oval head screws, leaks?...mostly non-existent. The second is for sanding, try the open mesh drywall sanding that is usually in the big box drywall section. Do it with water for max effect and zero dust. It won't cut real well, but much better than paper backed sanding. And after this project I can see work tables, kitchen counters, even the baths....watch out!
Yeah, I wanna see these being installed! Great info. Thanks.
Wanted to do that last Sunday but was not able. Hopefully very soon.
@@jtkilroy Did you end up installing them? If so, I'd love to hear about how you lifted them and set them into place. My largest windowsill is 10 feet long and 225 lbs and I am wondering what the best way to install it is.
Hi there, James,
thank you for this video. Did I miss an instalment? How did you form the drip-groove?
When setting sills in mortar use wet wood wedges. As the wedges dry they will shrink and easier to remove. Pull them out and point up the voids. Done this a lot and it works! Good luck and hope all works out for you, Greg.
Great tip, thanks.
Why not use plastic or lead wedges per the Precast Stone Institute?
sump oil works quite well as a release agent
Thanks for the details on that vibration motor! Call me crazy but that didn't seem quite as excessive as I was expecting.
Never the less I was surprised by the bubbles you had on the top surface after 4 minutes. How were the pinholes on the sides? Seemed like the position of the vibco unit did serious work on the perimeter - perhaps the field acted a bit like a diaphram and didn't vibrate as vigorously?
If you didn't show how dry the mix was before the superplasticizer I'd have said you added way too much water. Neat to see its effect on video instead of just a spec book. I might try mounting the vibrator on the end in a horizontal plane so the vibrations are back and forth not vertical.
That stuff is straight voo doo
Good video. When I've seen concrete vibrators used on construction sites they're moved around in the concrete but not for very long. Perhaps you could attach a steel rod to yours so you could use it like that. It might be more effective. This video is very helpful as we are going to make our own coping "stones" in concrete for a swimming pool
That's quite a project. You are probably going to want a sand only mix for that. It would be great to see some pics of that work.
@@jtkilroy Thanks James, yes, it is an interesting project. I've ordered a 1 inch diameter round nose router cutter from China to make the rounded edges for the moulds. We want a surface that is not slippery but not rough either. I also want to make corner stones with internal and external radii. So most of the difficulty is probably in making the moulds but the casting technique is important too. Plenty of experimentation will probably be needed. I have some good quality galvanised mesh to use as reinforcement. I've just rendered the whole pool with a sand-cement-SBR mix laid on damp background with a cement-SBR grout and skimmed it in a similar way but used a fine sand. I wish I'd videoed it now, it might have helped others. SBR is really sticky!
Use a saws all, no blade. Hold the foot against mold pull trigger. Works well
Ill get that a shot on the next one.
Can you post a quick video of those sill installed? I presume these are for your shop building.
I'd lay money on the "white water" having a high PVA glue content.
Cheers Eric
That makes sense.
Might be an acrylic latex or a styrene butadiene resin (SBR)
Hi James, I need to do a pour like this, but wasn't sure how! No I have a much better idea. Did you consider releasing agents like form release oil, or Thompson Water Seal? What do you think? Thanks
I just used what I had on hand. Honestly I can see how anything could work better than the Crisco. Literally the castings fall out of the mold.
Hey James. Thanks for the great video! I have a porch with brick window openings that I am enclosing and am about to tackle this same project. I have just a few questions for you if you have a moment:
1. Do you think the acrylic fortifier is necessary if I am going to keep the sills wet during curing?
2. Is the hogwire panel necessary for reinforcement or will just the rebar do? My sills will be 11" in depth.
3. Did you have any luck with any other methods of vibrating? It'd be nice to not have to buy a vibrator if I don't have to.
Thanks,
Nick
1. Honestly I am not sure. You can sure tell the difference when the mix is wet, ie pouring and curing. But, when they have cured a while they both look and feel the same. The fortified mix might well be stronger or more water resistant but without more experience I can't tell you really.
Related, though the acrylic fortifier is probably optional, I don't think the water reducer admix is. That stuff is amazing. I purchased it at the big box store. Its called "Rapid Set Flow Control". You can GREATLY reduce the amount of water in your mix with this stuff. I used one packet per sack of mix. Experiment a bit. I would mix up one sack REALLY DRY, think unworkably thick. Add one packet of that flow control and next thing you know the mix runs like water. It is amazing.
Question, what kind of mixer are you going to use?
2. The rebar would probably be plenty. For my sills I could have probably just used three sticks of 3/8 rebar and been fine. I had the 1/2 on hand so I used that. How thick will your sills be? You don't want the rebar too close to the surface otherwise it will show rust on the surface.
3. The palm sander worked great, you just have to stick with it for a while. Go all around the form, all sides and underneath. Also, before I vibrated the form I would go around with a hammer and knock on it. No matter which device I used I was mind blown with how much air came out of there.
@@jtkilroy Hey James. I just noticed that you responded to this. Thanks for taking the time to do that.
1. As far as a mixer, I was planning on just using a bucket and a handheld mixer like you did.
2. That makes sense. My sills will be 3" in height.
Going good don't drop it on your foot
A carage bolt in a hammer drill works well for settling concrete
I'm going to give that a shot
What about painting the sill, won’t the grease or Crisco stop the paint from adhering
I left the sills natural. Very little grease transferred to the finished part. A little, but you couldn't tell by eye, and could barely feel it.
I think your concrete was WAY to wet. More sand and less gravel will give a finer finish. I think you got those bubbles bad in the concrete because of there being too much water. Concrete works best when it is like dry mashed potatoes. Nothing wrong with the extra portland. I suggest using a lime mix to bed those in. A lime mix is much softer and will allow the building to move and not break. One of the most common mistakes in old building work particularly up north where we have freeze and saw cycles is repointing old brick structures with modern mortar mixes that have portland cement. The cement is too stiff and damages the brick, also it blocks water and holds it versus letting it free transport like in a lime mix. This leads to freeze jacking and damage.
Got two sacks of lime and sand just for the purpose of setting these.
@@jtkilroy I recommend finding a natural hydraulic lime if you can. I used some common hydrated lime and had to re do a wall after a year as it fell apart.
@@bcbloc02 it was all I could do to find the hydrated lime, this in a town full of 150 year old brick buildings. Of course we don't get much in the way of freeze thaw cycles here either.
You can get a better surface finish with the Butter flavor Crisco.... :)
And the window sills will taste better too.
How about a follow-up, wrap-up to the project? Lessons learned, etc.
Just f8nishend the install, video forthcoming
So you didn't go with in-situe casting, pity, you get a better finish as the smaller aggregates float when vibrated. You don't have to carry them about, and they are integrated into the wall!
These windows are 20ft above a busy sidewalk unfortunately. That and there are so many different widths, I'd end up having to build tons of molds.
@@jtkilroy I under stand but, an L shape the length of the longest, inside and out, 4 blocks to adjust for length and a piece fit in between the walls to form the slope out, could all be done from inside!
Why did you add the extra portland?
Because the concrete guy told me too, about as good a reason as any. He said it would make for stronger, more durable product.
@@jtkilroy good reason
What part of the country are you located ?
Mississippi
Today is Sept 15 and a hurricane is headed your way. It has already hit Pensecola pretty hard. and it looks like it may pay a visit to Keith Rucker. All of your watchers are hoping & praying that you don't get hit. Please keep us informed.
We are buckled down tight. Thanks for checking in, we appreciate it.
dang kilroy..you need a haircut !! lol.. i wonder if lowering the frequency of the vibration would give you better results? the high freq you're using seems to cavitate the material and create more air bubbles ...
I believe you are correct on both counts
Hi James. RUclips is getting greedy again. It would be great if you'd opt out of mid roll ads. I'll sit thru start and end, but five mid roll in 15 mins is too much for me.
No problem Sean, consider it done.
On the 13th of August RUclips turned off email notifications for computer users.
There is very little point in being subscribed, if we won't get notified... that stupid little bell on in the RUclips screen isn't going to do it.
Every creator, who wants to keep his subscribers, should insist that RUclips brings these notifications back. (and kick the idiot that dreamt up this daft idea out on the street!)
Paddy