A Forum For Modelers By Modelers.
 
HomeHome  PortalPortal  RegisterRegister  Log inLog in  

Share | 
 

 Mold for lead ballast

View previous topic View next topic Go down 
AuthorMessage
Damien
Captain (moderator)
Captain (moderator)
avatar

Posts : 2742
Join date : 2011-06-11
Age : 65
Location : Ballarat Vic. Aust.

PostSubject: Mold for lead ballast   Fri Jul 18, 2014 9:45 am

While ballasting models in the past I've used flat pine board and hardwood strip about 3/8" apart and cast the lead in 24" lengths and cut to needed length, with the Paddler models there's not much room and it's fiddly to place the strips.
So I used some Redwood 3/8" x 3 1/2" and drilled 30 holes of 5 sizes with spade bits 12mm to 28mm in size.

Now before anyone jumps up and down about safety.


The wood does scorch and smoke somewhat.
Though I've never had a fire, 
I wear my leather welding apron (Neck to ankles)
A fire extinguisher is close at hand.
It's always done out doors. 




Each casting will be a little bit bigger as the sides scorch,

and I expect to 5 or 6 castings from this Mold which should be enough for several more models.






After cooling I'll separate the 2 parts and the weight will tap out without hassle. 
Back to top Go down
nhp651
Captain (moderator)
Captain (moderator)
avatar

Posts : 2839
Join date : 2011-06-11
Age : 66
Location : Fleetwood Lancashire

PostSubject: Re: Mold for lead ballast   Fri Jul 18, 2014 12:24 pm

Ihave been known to do similar things myself in my younger days of rashness.........like pouring moulten lead down a copper pipe into a bucket of cold water to make lead shot.................

DON'T DO THIS AT HOME FOLKS...............TAKIE IT ROUND TO YER MATES HOUSE INSTEAD, lol!  lol!  lol!
Back to top Go down
Damien
Captain (moderator)
Captain (moderator)
avatar

Posts : 2742
Join date : 2011-06-11
Age : 65
Location : Ballarat Vic. Aust.

PostSubject: Re: Mold for lead ballast   Sat Jul 19, 2014 9:30 am

Interesting day in the past I've used a stewed fruit can to melt the lead in on a camping stove with a vice grips as a handle and was somewhat awkward so I added a pouring lip to an old soup ladle that I now use for paint and polyester resin.



About 3/4 poured.



Separated to assist cooling.



Back together ready for next casting not as much scorching as I expected
Also showing the product of the first cast.

 

The second cast went well with all slots filled things went haywire when I tried to tap the buttons from the mold I assume the heat destroyed the resins holding the wood together it split down the middle and ended in 5 pieces all is no lost I have 55 weights of various sizes.



This pic shows the approximate weight and sizes of the weights all up I managed to get 55 buttons in 5 sizes with an all up weight of 2.o45kg.



The lesson learned from this I believe to be larger gaps between holes on the mold & it should last longer.


Last edited by Damien on Sun Jul 20, 2014 10:02 am; edited 1 time in total
Back to top Go down
nhp651
Captain (moderator)
Captain (moderator)
avatar

Posts : 2839
Join date : 2011-06-11
Age : 66
Location : Fleetwood Lancashire

PostSubject: Re: Mold for lead ballast   Sat Jul 19, 2014 3:52 pm

that's interesting as I wouldn't have expected that especially as the stuff would be contracting when cooling , not expanding??
Back to top Go down
Damien
Captain (moderator)
Captain (moderator)
avatar

Posts : 2742
Join date : 2011-06-11
Age : 65
Location : Ballarat Vic. Aust.

PostSubject: Re: Mold for lead ballast   Sun Jul 20, 2014 1:08 am

Even cold they need to be tapped out that's when it fell apart, today I'll try casting some more in what's left of the mold.
Back to top Go down
Damien
Captain (moderator)
Captain (moderator)
avatar

Posts : 2742
Join date : 2011-06-11
Age : 65
Location : Ballarat Vic. Aust.

PostSubject: Re: Mold for lead ballast   Sun Jul 20, 2014 9:57 am

Success 5 more casts made before the mold fell apart all up I cast 3.9kg of buttons and used all the 2lt tub of wheel weights that were lead I through out most of the Nickel and Steel ones found a few in the slag when finished.
I also re-cast the lead strips I'd done in the past.






As the casting progressed the wood scorched more and more.






Until the wood fibers couldn't take the heat any longer  and fell apart along the darker lines in the grain.






The base board started flat and bowed upward at the edges more with each casting seen upside down with a square on it.






And finally the leftover slag along with some wheel weight that are either Steel or Nickel that wouldn't succumb to the blow torches heat.


 
Back to top Go down
Damien
Captain (moderator)
Captain (moderator)
avatar

Posts : 2742
Join date : 2011-06-11
Age : 65
Location : Ballarat Vic. Aust.

PostSubject: Re: Mold for lead ballast   Mon Jul 21, 2014 7:54 am

I found some lead  I'd forgotten while ballasting in the bathroom so I retrieved the mold bits from the waste bin and got 2 more castings from them albeit with a lot of the buttons joined together half an hour with a wire cutter fixed  them all.
Back to top Go down
Sponsored content




PostSubject: Re: Mold for lead ballast   

Back to top Go down
 
Mold for lead ballast
View previous topic View next topic Back to top 
Page 1 of 1

Permissions in this forum:You cannot reply to topics in this forum
TheRcModelBoatForum.com :: Technical Pages :: Tips & Tricks!-
Jump to: