Superior & Seattle Railroad Build (Volume 2) Started 2/25/17

[Mark Dalrymple]

That looks WAY better, John!

The way Dalabarre is a very similar colour to your rock work also works magic.  The eye is instantly drawn in to the lighter colours of Threadwell's which really pops.  It then makes the sideways transition to Dalabarre.  I think in this way the two structures don't seem to compete for the viewers attention, but are rather taken in one at a time.

I actually went looking at the SRM site after your last post (before I commented) to look at that end view.  I remembered a wonderful wooden stairway from the track level platform to the lower level door, kind of tumbling down on the roof.  Turns out that was just an addition I did to my scratch-build which I based on this kit.  I remember that stairway taking me 9 hours to construct!

Looking fantastic!  Cheers, Mark.

[S&S RR]

Followup to Hydrocal castings issue:  I few pages back in this thread you will find a discussion of my experience with old hydrocal castings for my Threadwell's build. Long story short one of the castings fractured during the molding process when I was making molds for a duplicate set of resin castings.  I decided based on that experience to make molds of my hydrocal castings for Delabarre's Tool and Die.  My theory being that the old hydrocal castings had become brittle.  Well, I pulled the mold boxes off the molds and castings today. I had three castings fracture from the Delabarre's batch.

[S&S RR]

Two of the castings are very repairable but I did loose some brick detail in the fracture zone. The third castings would require lots of repair hours to be able to use for a build. Here are a few photographs that show the issues.  First, this photograph of the castings just after I removed the mold box.  The castings are already broken before I even tried to get them out of the mold. I don't know if the breaks are caused by thermal stresses or if I did it while I was removing the mold box. The bottom line is that the casting are very delicate.

[S&S RR]

[S&S RR]

This closeup shows how the brick surface is breaking off in the mold.

[S&S RR]

So, the good news is,  that I have all the detail captured in the molds - so I can make resin replacement castings. The bad news is that I need to make molds of all of the old hydrocal kits that I have on the shelf to protect my investment. I need to check the rest of my SRMW kits to see if I have any more with plaster castings. I know I have some very old York kits that  I will need make molds from. Also, some C . C. Crow kits.
Anyway, I thought I would share this with the forum so you can decide what you want to do with your older hydrocal kits.

[vinceg]

Thanks, John. This is soooo useful. I have most of the early SRMW kits as well. In the early stages of my current build of Rugg, I had a couple of cases where a casting tipped over while standing them up and test fitting. Remarkably, no castings have broken. I didn't realize how lucky I have been. Hopefully I am out of danger with the Rugg build but there are many more to come (including Delabarre Tap and Die -- the first SRMW offering and one of my faves). I am definitely going to follow in your footsteps here to help protect those precious components.

[S&S RR]

Thanks, John. This is soooo useful. I have most of the early SRMW kits as well. In the early stages of my current build of Rugg, I had a couple of cases where a casting tipped over while standing them up and test fitting. Remarkably, no castings have broken. I didn't realize how lucky I have been. Hopefully I am out of danger with the Rugg build but there are many more to come (including Delabarre Tap and Die -- the first SRMW offering and one of my faves). I am definitely going to follow in your footsteps here to help protect those precious components.

Your welcome, I think it's the right thing to do. Bob's casting look so good.

[deemery]

Two thoughts:  (1) could your hydrocal be compromised/old?   (2) you could put gauze in the middle of the casting to help add some strength.  The gauze won't cause any problems cutting out the windows.


It's been interesting to read about your trials on making these castings.


dave

[S&S RR]

Two thoughts:  (1) could your hydrocal be compromised/old?   (2) you could put gauze in the middle of the casting to help add some strength.  The gauze won't cause any problems cutting out the windows.


It's been interesting to read about your trials on making these castings.


dave

Dave


All of these castings were made years ago with fresh hydrocal. The castings would be fine to build with if you didn't bump them during the building process or once they are on the layout. The problem is if you have a problem replacing a casting now is difficult or very expensive. Thanks for following along.

[bparrish]

John......

Consider a mold release.  I know they use it on fiberglass stuff for boats and such. 


I made some cut stone castings some years ago.  I used spray Pam non stick cooking stuff.  Once the hydrocal had REALLY kicked off a quick rinse in the kitchen sink with a mild soap took any oil off of the plaster.  I also found that the oil stayed on the mold for several castings.


I never had any problem getting paints or dyes to stick to the plaster thereafter.


WARNING  ! ! ! !  This does NOT work with common plaster of Paris.  It is too porous.

Hope this helps.

see ya
Bob

[S&S RR]

John......

Consider a mold release.  I know they use it on fiberglass stuff for boats and such. 


I made some cut stone castings some years ago.  I used spray Pam non stick cooking stuff.  Once the hydrocal had REALLY kicked off a quick rinse in the kitchen sink with a mild soap took any oil off of the plaster.  I also found that the oil stayed on the mold for several castings.


I never had any problem getting paints or dyes to stick to the plaster thereafter.


WARNING  ! ! ! !  This does NOT work with common plaster of Paris.  It is too porous.

Hope this helps.

see ya
Bob

Hi Bob


Thank you for the suggestion.


I have been using a mold release that I buy from Micro-Mart. These castings are breaking before I even try to get them out of the molds.

[bparrish]

John...


I have never "ganged" that many items in a sheet like that.  Is it possible that they are loading each other during the cure time?

Just thinking out loud here.

see ya
Bob

[S&S RR]

John...


I have never "ganged" that many items in a sheet like that.  Is it possible that they are loading each other during the cure time?

Just thinking out loud here.

see ya
Bob

Bob


I really think that the thermal stress during the curing process is what is causing the cracking. The artist foam holds the walls from moving.  I have no way of proving it, but I have made hundreds of castings over the years and haven't seen this kind of casting failure. If I was in the business I would spend the time to figure it out - but I have a solution by pour resin castings of the older hydrocal kits that I have purchased over the years - so I'm going to move on.  I did check and all of the SRMW kits that I have  to build after these two are all made with resin castings.   

[S&S RR]

Just one more point on this casting dilemma - it was the middle casting in the group that shattered. I will be making smaller mold boxes in the future, just in case.