Freerails Home 
Home Search search Menu menu Not logged in - Login | Register

Freerails IS ACCEPTING new Members ... To join Freerails ... See how to Register as a Member in the 'Joining Freerails' Forum

Best Wood???
 Moderated by: . Page:    1  2  Next Page Last Page  
New Topic Reply Printer Friendly
 Rate Topic 
AuthorPost
 Posted: Sun Jan 31st, 2016 01:20 am
  PMQuoteReply
1st Post
Bob D
Registered
 

Joined: Wed Apr 1st, 2015
Location: Portsmouth, Virginia USA
Posts: 674
Status: 
Offline
What's the best, reasonably priced, wood I should use for pattern making?

I want to make a master pattern of this engine:



I plan on making the master, then a rubber mold, followed by fiberglass and resin to make a boiler shell that will (more or less) fit over the engine O-scale Williams by Bachmann USRA 4-6-2.

The WbB engine is not quite 12" long, 2-1/2" wide, and 3" tall.  i would also need to get a piece for the tender.

Seaboard took 3 of their class-P Pacifics and enveloped them with sheeting, to end up with the streamlined look.

I think it can be done so that the fiberglass shell simply slips over the existing model, with some mounting points to make it strong and stay in place.  You can tell that's what SAL did by looking at the photo, you can see the original pilot under the outer skin.

I have common hand tools, no super milling machine (I do have a mini-lathe but doubt it will come into play on this), I need something easy to carve (not balsa) and that will hold its shape.  It has to be available in the US and not cost me any limbs ;)

BobD.



____________________
BobD
O-SCALE BPRC
Back To Top

 Posted: Sun Jan 31st, 2016 06:48 am
  PMQuoteReply
2nd Post
Robert Comerford
Registered
 

Joined: Thu Feb 14th, 2013
Location: Glen Innes, Australia
Posts: 588
Status: 
Offline
Bob, isn't a lot of your milled scale lumber made from basswood? A piece of that might do the job. The wood carvers recommend it for whittling.

regards
BobC

Back To Top

 Posted: Sun Jan 31st, 2016 08:42 am
  PMQuoteReply
3rd Post
Thayer
Registered
 

Joined: Sat Jul 5th, 2014
Location: USA
Posts: 104
Status: 
Offline
Bass and Mahogany are both valued for their tight grain and consistent carving characteristics for such work.

More readily available and affordable, I have also used MDF for pattern making, just glue up layers to make a block and start in carving with a bandsaw, rasp, hand plane and chisels to get what you want. Any low spots are readily filled with Bondo.

Once you have the desired shape, seal it with a high-build, sandable auto body primer for finishing.

Another option since you are planning a rubber mold (silicone), would be to make the mold out of plaster. I would rough out a box from scrap wood clamped together that is a little generous all around, drop in a garbage bag as a release, then fill with plaster. Once the plaster is mostly cured you could pop the box open and start carving.

Frankly, you could even work with foam and then seal it and harden the surface with a skim coat or two of thickened epoxy.

You don't really need much as a pattern for pouring a mold.

Thayer

Last edited on Sun Jan 31st, 2016 08:44 am by Thayer

Back To Top

 Posted: Sun Jan 31st, 2016 12:53 pm
  PMQuoteReply
4th Post
Bob D
Registered
 

Joined: Wed Apr 1st, 2015
Location: Portsmouth, Virginia USA
Posts: 674
Status: 
Offline
Thanks guys! I think basswood will work and is readily available at the big box lumber stores. An overall piece of 4"x4"x24" should be more than enough to do the boiler and tender.

BobD.



____________________
BobD
O-SCALE BPRC
Back To Top

 Posted: Sun Jan 31st, 2016 04:00 pm
  PMQuoteReply
5th Post
Herb Kephart
Moderator


Joined: Thu Jul 19th, 2007
Location: Glen Mills, Pennsylvania USA
Posts: 5870
Status: 
Offline
You Realize that you are going to have to make a three piece mould from your pattern. Each side, split down the centerline, and a ''plug'' for the space in the middle. When I ran the shop where we did this kind of thing for money, I made the moulds from rubber as thin as possible, constant with covering all the detail, then backed the rubber with plaster, for stability. this also saved money on expensive rubber. After the casting was made the plaster pieces were removed, and the thin rubber peeled off easily.

I would advise against getting involved with fiberglass on something that small. The whole fiberglass deal is messy, and you have to work quickly. You can easily get the rigidity that you need from one of the urethane casting resins, available in consumer (small) quantities from   smoothon.com  But first, you need a pattern. Popular is a popular, and less expensive wood for pattern work. If that was a pun--well--. What ever material you use for the pattern, seal it with several coats of Rust-Oleum gray auto sanding primer to get a smooth surface. remember that it is a lot easier in the long run to fix the pattern than the resultant casting.

We did several models of a corporate jet with about a 24'' wingspan using this basic process, and took the moulds off an existing, finished model that we had made previously for the customer--with out harming the painted finish

Once you get the pattern, I would be glad to take you step by step through this process, if you decide to go this way

Herb



____________________
Fix it again, Mr Gates--it still works!"
Back To Top

 Posted: Sun Jan 31st, 2016 05:01 pm
  PMQuoteReply
6th Post
Cor V
Registered
 

Joined: Wed Mar 11th, 2015
Location: Netherlands
Posts: 341
Status: 
Offline
i would go for MDF
it has no nerf (or how do you cal the wood lines)
it is verry fine in structure , and if you take severall pieces gleued togerther you will have a big piece

Cor



____________________
Cor
Back To Top

 Posted: Sun Jan 31st, 2016 05:04 pm
  PMQuoteReply
7th Post
W C Greene
Moderator


Joined: Fri May 4th, 2007
Location: Royse City, Texas USA
Posts: 8055
Status: 
Offline
That's a neat loco. I was wondering...do you want to make the superstructure casting(s) available for sale or is this a "on of" for you? Making loco parts for "the masses" is a good thing but you might consider (1) how many Seaboard modelers are out there and are any of them interested in this loco. (2) how much time/effort are you willing to invest in this project-and would the returns be reasonable for the time invested? and (3) if this is just for your railroad, then why not build the superstructure from styrene (much easier) and have something nobody else has?

I ain't trying to be a hard-ass but if you made this from wood, then it would need to be sanded, primed, sanded again, wood grain filled, sanded again and etc. Please consider making it from styrene, plexiglass, or get crazy and make if from brass-then it would be very durable.

Woodie-for what it's worth



____________________
It doesn't matter if you win or lose, its' how you rig the game.
Back To Top

 Posted: Sun Jan 31st, 2016 07:55 pm
  PMQuoteReply
8th Post
Bob D
Registered
 

Joined: Wed Apr 1st, 2015
Location: Portsmouth, Virginia USA
Posts: 674
Status: 
Offline
Herb and Woodie,

Thanks for all the info :thumb:

I've made a few molds before, so it's not new to me, except this will probably be the largest thing I've done (I did make a large mold for a wheel for a 1/6 scale confederate 12-pounder).

I'm sure if I make it a few folks will ask if I can make them one, but I don't know if I want to get that involved in it. If the 1st one comes out good then I'll decide.

Poplar is a good choice too, thanks!

I haven't thought too much about making it from styrene/plexiglass, but I do have a nice big sheet of 1/8" plexiglass I could use. I'm lousy at soldering large pieces of brass, but that is a possibility.

more later,

BobD.



____________________
BobD
O-SCALE BPRC
Back To Top

 Posted: Sun Jan 31st, 2016 10:44 pm
  PMQuoteReply
9th Post
Tramcar Trev
Registered


Joined: Sat Mar 16th, 2013
Location: Gordon ACT, Australia
Posts: 398
Status: 
Offline
A Patternmaker would use Jelutong because we cant get Basswood here.

I have used MDF laminated up to make a large lump, it works well as there is no grain and its dimensionally stable...:us:



____________________
There once was a man who said Damn!!
I perceive with regret that I am
A creature that moves
in predestinate groves
I'm not a Bus, I'm a tram
Back To Top

 Posted: Mon Feb 1st, 2016 12:50 am
  PMQuoteReply
10th Post
Bob D
Registered
 

Joined: Wed Apr 1st, 2015
Location: Portsmouth, Virginia USA
Posts: 674
Status: 
Offline
I'll have to check out the MDF, everybody seems to be pleased with it.

BobD



____________________
BobD
O-SCALE BPRC
Back To Top


 Current time is 07:58 am
Page:    1  2  Next Page Last Page  

Top



UltraBB 1.172 Copyright © 2007-2016 Data 1 Systems