New progress on the Morko ......now W/ SUCCSESS ! and NEW wax

[RocklockI]

making the mold halfs flat



Morko in the frame



Painting the frame so the silicone doesnt stick .



filling the frame with clay



relieving the clay for morko



Morko being sealed into the clay



Believe it or not putting the clay in and getting morko in takes ALL DAY to get it right ....And today with fingers crossed I get to see if I got it right ?

I poured the second half of the silicone mold yesterday ......sooo

Is this what you want Tom ?

If it all comes out ok I'll be casting morkos soonish,ish????ish  

Gary

ETA The mold halfs must be flat so that with just a kittle vasaline they will seal to not allow 100 dollars worth of silicone to run out all over the kitchen table !

The frames are pianted so the silicone wont go into the pours of the wood and stick .

The clay goes into make a 'plane' or line of seperation , Then morko goes in halfway .

Then ALL the little gaps between the clay and morko are sealed up using dental picks .

I will take photos of the mold parting as soon as I do it . Today sometime  
 

[dan610324]

now when you have done it one time you realize how many hours it can take until you got the clay tight to the master, but when I told you how long it could take I got the feeling that you didnt really believe me   

[carronader]

now that's hands on..........making and shaking.........I'm sure I'm not the only one who wants to see more of that kind of post.

[RocklockI]

Dan ,I dont know how to call up the old casting post ....maybe I should add it on to that post and not start a new one here .??

You said silicone wont stick to other silicone ,right Dan ?   

[dan610324]

I said that silicone dont stick to anything  BUT  other silicone

[seacoastartillery]

     Sounds like you saved his butt, AGAIN, Dan.   I can just picture the HUGE chunk of silicone with the Morko captured inside.   

Tracy and Mike

[RocklockI]

Alright , I pulled the mold apart ..MORKO LIVES !!!!!!



This is the stuff Plastisil 71-20 44.00 dollars for 2 lbs ,there are 4 lbs in Morko .



I was a bit   nervous with it at this point it wasnt supposed to come out as a one piece silicone brick .



First born pic ,the edges were kind tacked together but after running my finger all around I convinced it to come apart .



Jesus resurected for me ......!!!!!!! Oh happy happy ,joy ,joy !!!



Here he is just laying there ! isnt he beutifull   The many holes are for alignment of the mold halfs next pour with wax .

You can buy little molds for them ,OR Dan cuts little wedge holes in the silicon , I decided to use the bottom of a bic lighter .......then when you pour the second half the silicone will fill them in and then when it comes apart there are perfectly corrosponding holes to line everything up agian .

I will say this ,there have been a few odd moments while making the positive when it dawned on me that I was doing the exact same thing some brothercaster did in 1314  . No there is no positive date but thats the one I've assigned it . Sighting along the lines and angles to try and make it perfect . The other very interesting part of this endevor is the scribing on the sides and top . I did it the same way the first guy did !

Dan explianed to me how the curator of the museum in Stockholm Sweeden explianed it to him . The writiing is thought to be "Ava Marire" in Latin I'm guessing  . But the artist was not an educated man and he had seen it or been told it by someone learned ....I'm guessing a Monk .

He didnt write it correctly ! And he was only 'copying' what he had seen . Well I did the same thing , I had no clue what I was scribing into it , but its as close as I can do .

I'm very proud of it ,as I've only seen one other reproduction of Morko ,and it wasnt very good . IMHO

The only inaccuracies are the beard which is a bit long and the over all length .... I made it exact ,but apparently the clay shrinks a little bit ! so its about 1/4 inch too short .


Gary

ETA I am going to send one to Dan as a gift for teaching me this stuff . I want him to take it to the Curator and compare it to the origanal , and here what he thinks of it  . 

All I ask is that you get and post a pic of my morko next to the origanal .

Also no machines of any kind were used in making the positive ,just clay and fingers and a few dental type tools .

I'm  lucky that the positive survived  . Ill clean it up and display it !!!!






Gotta go inspect him good now ,

[gulfcoastblackpowder]

It's difficult to see if the detail was retained in the mold, but it looks very good.  Curious how much the Smee casting shrunk, since all castings shrink a little.  The final will probably be a little shorter still, not that it should matter much, since the overall dimensions would still be proportional.

It's coming along nicely!  I'm looking forward to further updates.

[dan610324]

a bronze casting shrinks approximately 1,6%

[RocklockI]

what I was talking about is the clay positive's shrinking . the thing was nutts on at first . It was a classic moment  """....YOU GOT TO BE SHAFTING ME %@#*! DAMIT ....wait maybe my memory is bad ? maybe I'm not rembering the Dim. of 7.6" ...

no it shrank .

live and learn ,Gary

[gulfcoastblackpowder]

So it'll probably be a total of about 3/8" smaller than the original (the current 1/4" for the mold and about another 1/8" for the casting)?  That doesn't seem very significant.

[gulfcoastblackpowder]

what I was talking about is the clay positive's shrinking . the thing was nutts on at first . It was a classic moment  """....YOU GOT TO BE SHAFTING ME %@#*! DAMIT ....wait maybe my memory is bad ? maybe I'm not rembering the Dim. of 7.6" ...

no it shrank .

live and learn ,Gary

Not sure I understand.  Does the model fit into the mold still?  If it does, how did it shrink?  Was the shrinking of the clay before final shaping with the picks?

[RocklockI]

Oh yes it still fits perfectly . The shrinking was while the clay got hard . Not the silicone .

I was totaly pisced off at myself for making it to small ,but I made it the right size ,it shrank .
I hope it doesnt shrink much in the bronze .

Gary

[carronader]

stop messing about and get the damn thing cast.................and congratulations Gremlin.......your enthusiasm is infectious.

[gulfcoastblackpowder]

Oh yes it still fits perfectly . The shrinking was while the clay got hard . Not the silicone .

I was totaly pisced off at myself for making it to small ,but I made it the right size ,it shrank .
I hope it doesnt shrink much in the bronze .

Gary

Ok, that means the total shrinkage will only be in the bronze, which should be around 1/8", which is hardly noticable, especially if they're not sitting right next to each other (though I'd also like to see some pics of yours with the original).

[GGaskill]

The real problem will be that the wax that is poured into the cavity in the silicone rubber will also shrink which will make the end product yet smaller.  That's why one makes "allowances" in the pattern to compensate for the various shrinkages.

One way to lessen the shrinkage in the wax pattern is to cast it hollow so the shrinkage is on the inside of the hollow wax pattern.  Do this by pouring the wax in the mould and sloshing it around to coat all of the inside surfaces, and then pour out the remaining liquid wax.  Do this several times, letting the whole thing cool down in between each sloshing.  You can seal the draining point after the fact with a piece of flat wax and a soldering iron.

[RocklockI]

The real problem will be that the wax that is poured into the cavity in the silicone rubber will also shrink which will make the end product yet smaller.  That's why one makes "allowances" in the pattern to compensate for the various shrinkages.

On way to lessen the shrinkage in the wax pattern is to cast it hollow so the shrinkage is on the inside of the hollow wax pattern.  Do this by pouring the wax in the mould and sloshing it around to coat all of the inside surfaces, and then pour out the remaining liquid wax.  Do this several times, letting the whole thing cool down in between each sloshing.  You can seal the draining point after the fact with a piece of flat wax and a soldering iron.

Well , George , One 'may' or 'may not ' make allowences to compensate , as but this can only happen after one has done this B4 I was clueless and profess alot of ignorance in these matters ,but I'm tryin ....

I could not care less about the bronze shrinkage ,or the wax shrinkage ,the clay shrinking was a surprise . I'm going for a full solid wax cast ,unless Dan tells me too .

I have my rules on these things . I am only an Eb to his Oliver !    Cee?

Gary

Dan , Eb was a hired hand in a TV show here in the 1960's called Green Acers . His boss Mr. Oliver Douglas and his crazy hot wife Lisa (Eva Gabor) hired Eb and he was a ...piece of work ! And one of my personal heros , EB . Oliver too ,but mostly Lisa Douglas . oh hubba hubba ...

BTW if anyone did NOT know Eddie Albert who played Oliver was a for real hero from WWII . He was a coxsin (sp) ,a Higgins boat driver at Tarrawa IIRC . His boat got suck on a reef . His Marines were jumping overboard as a stuck Higgins boat is not were you'd want hang around .....! Bullet magnet !

Some of the Marines were not doing too good trying to stay afloat and on their feet with all the crap they had strapped to them .

Eddie jumped from his post (boat) to save them ( actually abandoning his post ,which is not something you'd do and expext any carreer at all /or freedom ! )

Then he got back on the boat and backed it away to go get more Marines ....! Semper Fi Mr Eddie Albert !

Loved your show ! ....and Lisa too ! 


Gary

[dan610324]

hollow wax originals is a very very good thing for larger objects
but we just havent come there yet
its too much to learn at once if I would try to tell every little detail from the begining
must do it a little step by step

a standard soldering iron is not so good to use on wax
even the temp adjustable irons is too hot
they usually got a working temperature between 200 and 500 celsius
the different waxes that I use got melting temperatures between 58 and 75 degrees celsius
when Im working on a wax with a 58 degrees melting temp I have my wax working pencils adjusted to 62 degrees celsius
this pencils are adjustable between 50 and 200 degrees celsius
and they got 6 different shaped and sized tips

[KABAR2]

Gary,

You may have covered it but it's 3 in the morning and I may have missed it.....

Just out of curiosity did you de-gas the silicone when you did your pour?  Did you have much problems with bubbles?

I built a vacuum chamber for doing this it saves a lot of grief.

[dan610324]

Ive also been thinking of a vacuum chamber , both for the silicone and the investment
but I havent found any suitable material to use yet

what do you use as the pump ??
I have been thinking of a refridgerator compressor

then I got posibilities to both get vacuum and pressure
if so it could also been used to vacuum dry wood and fill the chamber with linseed oil when still on vacuum
when its filled just change hose and pressurise the oil to really go deep in the wood
with some luck I belive I could totally penetrate a 2x4" with linseed oil

[KABAR2]

I picked up a medical evacuation pump at a yard sale, but it is identical to the compressors used for hobby air brushing,
the chamber is a 30mm ammo can you need to reinforce the lips of the can where the lid latches on so that it does not
collapse If I have time today I will photograph the set up it's at work, it has gone through two upgrades in chambers,
I originally used this at home for some 1:6th scale projects, with a SAW can, (a 50 can on steroids)  then went to a
WWII 40mm can and finally a 30mm can (larger) .

[cannonmn]

Sorry I'm lost, is this the second part of an earlier separate discussion?  I've never cast anything this way so I gotta ask.

1.  Where did the yellow thing come from in the first place (image of Morko)?

2.  What's the clay for?

Maybe someone just stating the basic steps in the process pictured would help, like:

1.  Put clay in a frame and dodis

2.  Take it apart and dodat

3.  ................

[RocklockI]

 The yellow thing is a clay positive I made . It is set into the white clay which is the parting line . Also it creates a 'plane' for the othe side of the mold to be poured onto . The wooden frames where squared on Seacoasts suface plate with sandpaper .

I relieved the clay instead of pushing it into because my clay positive would have broke . With a metal positive you could just push the positive into the clay then push all the displaced clay back around with dential picks it must be tight agianst the positive so no silicone runs undernieth the posoitive . The painted frame along with a thin layer of vasiliene  keeps the silicone from being stuck to the frame . Then Dodat 

This takes a long time .diddat 

Then Dodis  ,you put a thin layer of thinned vasaliene on the clay plane and a very light coat on the positive .

Then you mix up and pour the silicone into one corner and one corner only . AND in a very thin jet or stream so the air bubbles break up in the stream . Dodat andodat NOW !

Make damn sure nothing is leaking from between the flatened frame halfs sealed with vasiline . Dodis

Wait 24 hours diddat

Turn it ober and Dodis Dig out all the clay that was supporting the morko positive ,get off all old vasiliene off of your newly cured silicone half way up .

Then Dodis put a new layer of thinned Vasiliene on the silicone flat suface make sure the frame halves still have enough vasiline to not leak the second time .

Now mix up another two pounds of silicone and pour it in the second half ,dodats 

Then wait another 24 hours to seperate the halfs . diddat too

This brings us to today , John are you pickin up what I'm layin Down ? Good .

Now dodis  I'll cut a sprue and nesseary air vent as there are some air spaces that would be trapped ,and then start pouring wax , to achieve a stunning wax positive .

U CEE ? its easy  more stuff can go wrong than go right . From creating the origanal positive and trying to figure out how to make the positive .

To the mold making in silicone which is where I'm at on this now . Then learning to make wax positives correcly, on and on .

Eventually the wax will be 'invested' in the flask contianing investment . Then melted out and refilled with molten Bronze .

I hope this helps .

Gary

[cannonmn]

Thanks for the extra explanation, I'm starting to see it now.  Somehow I thoght the clay thing was two-sided and that didn't make sense.  If anyone else is behind in the understanding department, I think what Gary is doing is:


1.  Make one-sided silicone mold with negative model impression.

2.  Use that to make matching opposite side of silicone mold.

3.  Prepare silicone mold and cast a wax positive model between the two halves.

4.  Build flask around wax model, prepare risers etc., bake out the wax, and pour molten bronze into it.

Gary is working to get all the details right and so is explaining it from that aspect.  I couldn't see the forest, y'know, so I appreciate the extra explanation for thems of us what be a bit slow on de uptake, as they say.

[seacoastartillery]

 The yellow thing is a clay positive I made . It is set into the white clay which is the parting line . Also it creates a 'plane' for the othe side of the mold to be poured onto . The wooden frames where squared on Seacoasts suface plate with sandpaper .

Gary

     Whoa Gary!!  Let's not give these good folks the wrong idea.  The 2.5 x 3.0 ft. former granite surface plate, grade 'B' which has been converted into a woodworking fixture IS NOT our current or former INSPECTION SURFACE PLATE, 4.0 x 6.0 ft., Grade AA, precision metrology tool.  After going nose to nose with engineers, managers, buyers, expeditors and assorted inspecion lab layabouts and chastising them for years and years for putting coffee, soda pop, brief cases, wrenches, etc., etc., etc. on our various Corporate surface plates, we aren't about to allow even a little piece of sandpaper on our precision metrology plate!

     So, let's see ifn I understand your most recent explanation of how to prepare an investment mold.  Even though I don't have enough money anymore to even pay attention, I sure did carefully read your tome above.

     If I do find a way to pay attention and Dodis before I Dodat, then yor sayin, as far as larnin the technik, I can say I Dondat or Diddat, right?  

Keep going, as you are, beyond excellence, Gary!

Tracy and Mike

    

[gulfcoastblackpowder]

Hmmm...I get dis, but dat...?  Do I do dis before dat or dodat then dodis, and having donit, be done with it?  Oi, I think I'll just let you doit...

So, is the silicone reusable for multiple castings, and if so, what would be the run limit, if any?  I assume the wax would have to be recast, since it's melted down to make the investment, and the investment is "lost" during the stage that makes this lost wax casting, but it seems like the silicone should be reusable a number of times.  Is the only reason for the clay to avoid using more of that expensive $ilicone, or does it provide more support for the wax than silicone would?

[RocklockI]

CMan yes you are correct .

Gulfcoast yes the silicone is reusable to make wax positives .

The clay is used to support and seal the positive . If you were to suspend the positive and pour undernieth or sink it into silicone you would have lots of little bubbles up against the bottom of the positive .This way as air bubbles rise they are only on the outer surfaces of the mold instead the inside against the bottom of the positive  .

I know this didnt read very clearly ,I am sorry for that ...But I hope it helps .

Gary

[GGaskill]

The reason for the clay is to be able to "divide" the original (pattern) in half and make a silicone rubber (RTV, for "room temperature vulcanizing") mould of half of the object.  After the first half has set, the clay is removed and replaced with more RTV to make the other half of the mould.

[carronader]

don't have anything to do with casting because one mistake and you've blown the deal..........Diddat.

[gulfcoastblackpowder]

The clay is used to support and seal the positive . If you were to suspend the positive and pour undernieth or sink it into silicone you would have lots of little bubbles up against the bottom of the positive .This way as air bubbles rise they are only on the outer surfaces of the mold instead the inside against the bottom of the positive  .

I was thinking it may be there for support...

The reason for the clay is to be able to "divide" the original (pattern) in half and make a silicone rubber (RTV, for "room temperature vulcanizing") mould of half of the object.  After the first half has set, the clay is removed and replaced with more RTV to make the other half of the mould.

You know, I'd just read that, so I don't know why I missed it, but yes, the clay would do a much better job of dividing the positive than using a more fluid material, like the RTV, by itself.

On the other hand, you wouldn't want to only use the clay because, though it could provide the form of the positive, it can't pick up the fine detail as well as the silicone.