Green sand molding methods

[ironman]

  Hi everyone
                      I have made two videos of two different methods for making sand molds.  One is about using one pattern to make two castings and the other is about using a one piece pattern and establishing a parting line in the mold.

 

[Fredbare]

Thanks for sharing ironman, excellent work, and well videoed.

John

[doubleboost]

Nice videos
Very well made 
A commentary would make them better
John

[vtsteam]

Masterful job molding, casting, and videoing as usual!   

[ironman]

Thankyou for watching the videos.

 doubleboost I did try commenting on one of my videos, but after endless takes it took a lot longer to make and also my Australian accent will be hard to understand.

  Have a look at  this video and tell me if you can understand my comments

[doubleboost]

Your accent is great
My Geordie accent is the problem
John

[SwarfnStuff]

No problem at all with your accent Ironman. Then again, I am also from the land downunder  Comentary would be nice but I also understand there is a lot more fiddling involved. Great video on the samd mould casting though.

[andyf]

Ironman, your  commentary was perfectly clear to me, too.

Here in the UK, which is pretty small, we have such a large variety of regional accents that we get used to deciphering what folk who live quite nearby are saying. I live near Manchester, but 40 miles west is Liverpool, with its own distinctive accent. 40 miles east and I'm in Sheffield, where they speak South Yorkshire. In turn, their accent is different from the north of that county. Keep going north from there and you get to John Doubleboost's territory, with its own accent, dialect and a slightly different rhythm of speech. I'm sure it's the same in the US, though mainly over longer distances. 

Andy

[vtsteam]

Besides, it's fun learning accents! Adds flavor to the videos.

But I also appreciate the ability to communicate what you're doing without words, and if it means more fine videos that way, great!

[Sid_Vicious]

I'm Norwegian and I had no trouble understanding you.  Since English isn't my mother tongue there is sometimes some words I struggle with, but that is mostly technical and jargon words. 

[micktoon]

Hi Ironman , no problem with your accent here either , my accent is the same as John Doubleboost, as stated so many accents about its all a game tuning into them and also good to hear all the various accents on videos about the net..................... I think I got yours strait off because of the Fosters adverts  maybe
 All good videos anyway , so whatever the mood takes you I say , but I think most people would enjoy your accent as awell as understand it no problem..... keep up the good work 

 Cheers Mick

[ironman]

Thank you for all your replies.

I find making comments distracting even more so when ramming a green sand mold which requires your undivided attention.
 
Also I have to make sure that I don't block the camera's view. I am finding out that making videos is not as easy. I find subtitles  easy to use.

[Meldonmech]

Hi Ironman,
                    You made some fine castings, and video's, I find you get much better castings using aluminium machined patterns. Do you use CO2 cured cores?

                                                              Well Done       Cheers David

[ironman]

Meldonmech

                   Patterns are made from fine grained timber which can be expensive or hard to find so I use what is in my workshop. I use a lot of aluminium billets cast from scrap and plastic sheets that were old for sale signs. These items do not crack split or have grains in them like timber so are perfect for patterns.

A long time ago I used Co2 cores but lost interest because of cost and very poor post casting breakdown. A very cheap alternative is portland cement for cores and molds. Use about 8-10 % cement and about 4% water then wait for 3-5 days to set.

[awemawson]

Mix icing sugar with the sodium silicate for an easy breakdown of CO2 cores

[vtsteam]

A very cheap alternative is portland cement for cores and molds. Use about 8-10 % cement and about 4% water then wait for 3-5 days to set.

Thanks Ironman, I'm going to have to try that!

I'd been using molasses water and wheat wallpaper paste and baking them. But the baking part is tough to arrange with SWMBO, and energy wasteful unless you have a lot of cores -- I don't usually.

I guess the cement just calcifies at high temp. Does it work for aluminum castings , too, or just iron?

[ironman]

vtsteam

             It works with both and I use coal dust in cores for iron castings.

 awemawson

                     I did purchase sodium silicate with molasses mixed in and found it caused blowholes when used as cores. The sodium silicate I purchased before and after the molasses batch never gave any problems with blowholes in cores.

It has to be purchased from a foundry supplier which are not friendly to backyard casters so now I experiment glues or binders that can be purchased from my local hardware shop.

[doubleboost]

This method works for me
I have bought some sodium silicate but not used it yet
John

[vtsteam]

Meldonmech

A long time ago I used Co2 cores but lost interest because of cost and very poor post casting breakdown. A very cheap alternative is portland cement for cores and molds. Use about 8-10 % cement and about 4% water then wait for 3-5 days to set.

Ironman, I'm about to make some cores following your recipe -- just wondered, are your mixing proportions by weight, or volume?

Also same question for your greensand mix given on Youtube for iron casting -- weight or volume?

(I'm also thinking about making a power muller similar to yours in the video. I think I have a similar big cast roller in my scrap pile)

Thanks!

[vtsteam]

Update on the above -- I was impatient to try it, so I thoroughly dried out some sand -- spread out on a board in the sun, weighed it and added 9% by weight Portland cement and 4% by weight water.

I then tried to extrude a 5/8" x 5" cylindrical core using a piece of PVC pipe split on one side as a core box and the slit closed up with two hose clamps, per Doubleboost's video.

 I used a 1/2' dowel to ram the mix, and to act as a plunger when trying to push out the core after the clamps were released.

I had little luck -- if I rammed it hard it wouldn't extrude at all. If I rammed lightly and it did extrude, it had no wet strength and crumbled to bits.

I played around with more water and cement, and got a little better wet strength, and I widened the slit in the pipe with a hand saw which made extruding a little more likely -- but still was unable to get a single solid core. I suppose I could widen the slit further -- the only problem with that is, the clamps make the finished core diameter smaller in inverse proportion to the size of the slit -- the bigger the slit, the smaller the core. I wanted one about 5/8" -- which is just about exactly what you get from a 1/2" nominal water pipe here.

So, questions:

I'm wondering if the mix recipe assumed damp, instead of thoroughly dry, sand (which would have increased the proportion of both water and Portland cement).

Or was based on volume instead of weight?

Also whether this type of core actually needs to come out of a mold before curing?

Maybe extruding is the wrong idea. Since it is Portland cement based, it can cure in an enclosed space --  so maybe that's what ironman does.... ?