[IDEA] resin bond sand

[oldgoaly]

Well after umpteen years of wondering how I'm going to make these heads, resin bond sand is what the big boys use. Just an idea to throw out there see if anyone salutes or fall over laughing.....
what about using sodium silicate aka water glass. cure it pull pattern?

Here are some pics
   

   

   

These are Villier's 49-125cc heads, rare as hens teeth (well good ones) well maybe John or Graham have a dust bin full of these in good nick?

[TomG]

I've heard of boiled linseed oil being used as a binder, just bake to cure.

Tom

[Mayhem]

What is on the underside? It may be easier to cast these as a solid and then mill the fins...

[dallen]

it may work if you can get it to release from the head, me I think I would make a silicon rubber mold and make wax ones and invest them, with the bolt bosses, you can't just mill the slots plus they wouldn't look the same.

From looking at them I would almost say that they were injection molded,

Fins are a pain in the butt to mold and cast and get them to come out right.

what ever way you go your going to need some good ones to make the molds off of.

DA

[the artfull-codger]

(09-20-2013, 08:39 PM)oldgoaly Wrote: Well after umpteen years of wondering how I'm going to make these heads, resin bond sand is what the big boys use. Just an idea to throw out there see if anyone salutes or fall over laughing.....
what about using sodium silicate aka water glass. cure it pull pattern?

Here are some pics






These are Villier's 49-125cc heads, rare as hens teeth (well good ones) well maybe John or Graham have a dust bin full of these in good nick?

The local foundry I frequent would cast these with co2 ,the fins don't look that fine & co2 is a strong sand, I had a few villiers engines mainly 9e 197s & more rare 250s but beermaker blagged them off me!! stuff still turns up at autojumbles round here.
Graham.

[the artfull-codger]

(09-20-2013, 09:34 PM)TomG Wrote: I've heard of boiled linseed oil being used as a binder, just bake to cure.

Tom

Tom I use boiled linseed oil & dextrin mix but only for cores & it's a very strong sand when baked but not really strong green, I usually mix some bentonite in to give it more green strength even then it's fragile.

[doubleboost]

(09-25-2013, 03:25 PM)the artfull-codger Wrote:

(09-20-2013, 08:39 PM)oldgoaly Wrote: Well after umpteen years of wondering how I'm going to make these heads, resin bond sand is what the big boys use. Just an idea to throw out there see if anyone salutes or fall over laughing.....
what about using sodium silicate aka water glass. cure it pull pattern?

Here are some pics






These are Villier's 49-125cc heads, rare as hens teeth (well good ones) well maybe John or Graham have a dust bin full of these in good nick?

The local foundry I frequent would cast these with co2 ,the fins don't look that fine & co2 is a strong sand, I had a few villiers engines mainly 9e 197s & more rare 250s but beermaker blagged them off me!! stuff still turns up at autojumbles round here.
Graham.

I used to race karts with 197 Villiers engines
Then went on to 100 national
John

[oldgoaly]

I have 3 Villiers powered 98cc James Comet, not sure what size the Monet-Goyon is and last but not least is a 125cc rebadged Excelsior Waratah. Plus while looking for various parts I've found a 49cc Excelsior Spryte motor and a 250cc Twin.
I did find some good reading on using water glass cured sand, but like some many technical write ups it butt-numming boring!