JPZ66

Hi All,
 
Colin answered that pretty well. The quality of the master is very important......especially in resin casting, what you see is what you get.
 
You choose an appropriate resin to cast with and along with well made molds ( a big key here ), you get your castings.
 
Metal is a bit more involved..... Typically metal castings are done on centrifugal casting machines, using vulcanized rubber molds. The caster must have a good understanding of many factors that come into play.
 
White Metal is a generic term. There are many formulas to be had here, depending upon the mix. Tin, Antimony, and copper are the primary metals used in this mix, and the casting properties can be affected by the ratios of each metal used. Furthermore, the purity, the temperature, the spin speed, flow distance, part orientation and plate pressure of the mold clamps can all play a part. Most casters develop their own feel for it and manage to come to workable settings for the type of casting they do. It is part science, and part experience. Play with any of those variables and you can have any number of quality issues....mis-cast, porosity, drossy or dirty parts, brittle or crystalized looking parts, etc. Get them all right and you have clean, crisp, dense and well structured parts.
 
Trust me, there is a learning curve to production white metal casting !
 
As for the finished items and how do different materials compare, if the quality of the castings are equal - be they resin, metal or some other material, well painted and detailed parts will show no difference. For the hobby modeler who wishes to make castings, I would recommend RTV silicone molds and a low odor casting polyurethane resin.
 
- Joe

Each of the parts shown here were cast in RTV molds
Kurt
 
 

Hi All,
 
Colin answered that pretty well. The quality of the master is very important......especially in resin casting, what you see is what you get.
 
You choose an appropriate resin to cast with and along with well made molds ( a big key here ), you get your castings.
 
Metal is a bit more involved..... Typically metal castings are done on centrifugal casting machines, using vulcanized rubber molds. The caster must have a good understanding of many factors that come into play.
 
White Metal is a generic term. There are many formulas to be had here, depending upon the mix. Tin, Antimony, and copper are the primary metals used in this mix, and the casting properties can be affected by the ratios of each metal used. Furthermore, the purity, the temperature, the spin speed, flow distance, part orientation and plate pressure of the mold clamps can all play a part. Most casters develop their own feel for it and manage to come to workable settings for the type of casting they do. It is part science, and part experience. Play with any of those variables and you can have any number of quality issues....mis-cast, porosity, drossy or dirty parts, brittle or crystalized looking parts, etc. Get them all right and you have clean, crisp, dense and well structured parts.
 
Trust me, there is a learning curve to production white metal casting !
 
As for the finished items and how do different materials compare, if the quality of the castings are equal - be they resin, metal or some other material, well painted and detailed parts will show no difference. For the hobby modeler who wishes to make castings, I would recommend RTV silicone molds and a low odor casting polyurethane resin.
 
- Joe

Ok,
 
I will order some fresh materials and put something together. I will use some small ship parts of course !
 
In the photo from Chuck, you can see an example of 'bottom feed'....pour the resin into the fill port and it goes down, over and then comes up to fill the mold cavity....this allows air to escape, rather than pouring direct and trapping air in the process. It is an example of the best method, in my opinion ....you will use a bit more rubber when making a mold this way, but you have a much better chance for success. Anyhow, I will be happy to expand on the process and will submit a tutorial to Chuck in the very near future.
 
-Joe

Ok,
 
I will order some fresh materials and put something together. I will use some small ship parts of course !
 
In the photo from Chuck, you can see an example of 'bottom feed'....pour the resin into the fill port and it goes down, over and then comes up to fill the mold cavity....this allows air to escape, rather than pouring direct and trapping air in the process. It is an example of the best method, in my opinion ....you will use a bit more rubber when making a mold this way, but you have a much better chance for success. Anyhow, I will be happy to expand on the process and will submit a tutorial to Chuck in the very near future.
 
-Joe

Would anyone be interested in a detailed tutorial on Resin Casting ? Both 1 pc and 2 pc mold making ? If there is enough interest I will pull some equipment out and put something together.
 
- Joe

Would anyone be interested in a detailed tutorial on Resin Casting ? Both 1 pc and 2 pc mold making ? If there is enough interest I will pull some equipment out and put something together.
 
- Joe

Sorry I missed this thread.....
 
Couple of observations...... Early in the thread it was mentioned to buy a few cannons and make molds and pour resin copies.....hmmm, even though you only intend them for your own use, and not for sale...it kinda takes away from the time and effort of the person or company who created the master in the first place.....no ?
 
Anyhow, since you have already chosen your materials, I won't go into those...let me offer some technique advice instead. Have some really fine cornstarch powder on hand. You will use that to 'dust' the interior mold cavity. After doing that, turn the mold (if single piece) upside down and tap the mold a few times with your hand to remove excess powder.
 
When you pour the resin, it helps to use a narrow rod...you hold that to the edge of the cup with the other end of the rod slightly inside the mold opening, then pour the resin down the rod and into the mold. After pouring the resin into the mold, give the mold a few gentle taps, then allow to cure.
 
I will tell you though that when you make the silicone molds, it is best to do a vacuum degassing of the material right after it has been thoroughly mixed. Then you pour nice and slow, Pouring a thin amount over your part, then moving off to neutral areas and allow the mold box to fill from the bottom up. Try not to introduce any bubbles when you pour.
 
Also, for general discussion......often times when you see resin parts that have voids or 'bubbles' , it is not that the part needed to be pressure cast or vacuum cast...I have cast thousands of parts right on the bench in normal atmosphere.....the voids you see are mostly due to either the wrong viscosity of resin, poor mixing and mostly, poor flow of the mold cavity. Humidity also has a big impact. Most of the poly resins are hydroscopic and the moisture absorbed then boils during the chemical reaction phase and wants to 'outgas' and gets trapped due to the quick curing process.
 
Your mix of A and B must be fairly accurate, and you want to try and find the lowest viscosity material so that it flows well and gets into all the detail. Mix in small batches, and keep the temperature on the low side of what the manufacturer calls for....this will slow the reaction down some and give you more time to mix and pour.
 
Silicones Inc, makes great mold making silicones for the hobbyist, and PolyTek and Alumalite make good resins for easy pouring.....there are literaly hundrds of formulas out there, and you can even make 'cold cast bronze' cannons. It involves mixing super fine bronze powder into the resin ( side A) then mixing that to B...and you pour that into a mold that has been dusted with the same bronze powder......resins can be colored also using dyes.
 
I started making molds and castings 15 years ago, and did a lot of production work for various companies along the way. At any rate, if anyone has questions about resin casting or mold making, feel free to ask. I will try to help if I can.
 
Joe

Would anyone be interested in a detailed tutorial on Resin Casting ? Both 1 pc and 2 pc mold making ? If there is enough interest I will pull some equipment out and put something together.
 
- Joe

Would anyone be interested in a detailed tutorial on Resin Casting ? Both 1 pc and 2 pc mold making ? If there is enough interest I will pull some equipment out and put something together.
 
- Joe

Cornwall Model Ship has 35mm ships crew figures... Sailing ships crew. 35mm works out about right for 1/48-1/50 scale. The figures were reasonably priced too.
 
Joe

Would anyone be interested in a detailed tutorial on Resin Casting ? Both 1 pc and 2 pc mold making ? If there is enough interest I will pull some equipment out and put something together.
 
- Joe

Pewter or other formulas of white metal are best cast in vulcanized rubber molds on a centrifugal casting machine. This process will yield high quality, crisp detailed castings. Not to say you can't do it with gravity pouring, low temp metal into quality RTV silicone molds, but is a lot harder to get fine details. Brass is a different animal.
 
Do the parts have to be metal ? Well detailed castings can be made at home much easier with low viscosity casting resins in RTV silicone molds.
 
Once painted and installed, only the builder will know what the details are made from.
 
- Joe

Bravo ! The ship looks really great Vivian. Love the photography too ! I look forward to seeing the Red Dragon next..
 
-Joe

Sorry I missed this thread.....
 
Couple of observations...... Early in the thread it was mentioned to buy a few cannons and make molds and pour resin copies.....hmmm, even though you only intend them for your own use, and not for sale...it kinda takes away from the time and effort of the person or company who created the master in the first place.....no ?
 
Anyhow, since you have already chosen your materials, I won't go into those...let me offer some technique advice instead. Have some really fine cornstarch powder on hand. You will use that to 'dust' the interior mold cavity. After doing that, turn the mold (if single piece) upside down and tap the mold a few times with your hand to remove excess powder.
 
When you pour the resin, it helps to use a narrow rod...you hold that to the edge of the cup with the other end of the rod slightly inside the mold opening, then pour the resin down the rod and into the mold. After pouring the resin into the mold, give the mold a few gentle taps, then allow to cure.
 
I will tell you though that when you make the silicone molds, it is best to do a vacuum degassing of the material right after it has been thoroughly mixed. Then you pour nice and slow, Pouring a thin amount over your part, then moving off to neutral areas and allow the mold box to fill from the bottom up. Try not to introduce any bubbles when you pour.
 
Also, for general discussion......often times when you see resin parts that have voids or 'bubbles' , it is not that the part needed to be pressure cast or vacuum cast...I have cast thousands of parts right on the bench in normal atmosphere.....the voids you see are mostly due to either the wrong viscosity of resin, poor mixing and mostly, poor flow of the mold cavity. Humidity also has a big impact. Most of the poly resins are hydroscopic and the moisture absorbed then boils during the chemical reaction phase and wants to 'outgas' and gets trapped due to the quick curing process.
 
Your mix of A and B must be fairly accurate, and you want to try and find the lowest viscosity material so that it flows well and gets into all the detail. Mix in small batches, and keep the temperature on the low side of what the manufacturer calls for....this will slow the reaction down some and give you more time to mix and pour.
 
Silicones Inc, makes great mold making silicones for the hobbyist, and PolyTek and Alumalite make good resins for easy pouring.....there are literaly hundrds of formulas out there, and you can even make 'cold cast bronze' cannons. It involves mixing super fine bronze powder into the resin ( side A) then mixing that to B...and you pour that into a mold that has been dusted with the same bronze powder......resins can be colored also using dyes.
 
I started making molds and castings 15 years ago, and did a lot of production work for various companies along the way. At any rate, if anyone has questions about resin casting or mold making, feel free to ask. I will try to help if I can.
 
Joe

I have read a number of books on the subject and the thing that struck me was that while there were many differences depending on which navy and whether it was a merchant or warship, one of the biggest influences was the Captain and senior officers of the ship. When you get to reading actual diaries or ships logs, the hollywood romance of 17th, 18th or 19th century sailing is quickly lost !
-Joe

Hi All,
 
In regards to painting scale models, there are a lot of different ideas and suggestions about how to deal with "scale effect", and ultimately it will come down to experimentation and what you find acceptable. You can find this topic out and about all over the 'net for different subject matter...airplanes, cars, ships, etc.
 
Here is a link to one such article : http://titanic-model.com/paint/LINK%20PAGE_Painting%20your%20model%20for%20the%20greatest%20realism/Painting%20your%20model%20for%20the%20greatest%20realism.htm
 
I know that I find the correct base colors are often too intense, and therefore will tone them down to some extent in most cases, and usually apply some degree of weathering as well. I also totally agree that models should neither be full gloss or full flat either. I have often mixed a flat coat with some gloss until a desired sheen is acheived ( yes, I spray through an airbrush nearly all of the time ).
 
In regards to bright white, some suggest a touch of grey mixed in to tone it down, and this may well be alright, but the result is a 'cold' color....works well on a metal based subject in my opinion. However, don't be afraid to try toning down the white with a warm color, such as tan or a hint of yellow....this will also bring the intensity of white down, but on the 'warm' side of things..... Again, experimentation is the key to finding what you like and practice on the same materials as your model before you take the plunge !
 
One other item for thought.....the base coat of a painted model will invariably play a part in the look of the finish coat....i.e; dark or light primers can have a subtle impact on what color you see in the end.
 
One other trick.......spraying flat paint is far more controlable and the flats dry quickly with less chance of runs developing. I therefore almost always paint in flats, and if the end product requires a higher level of sheen, I will take care of that in the clear top coats. Well, unless the subject is a scale model car or something that needs the highest gloss level possible.
 
Cheers,
 
Joe

Piet,
 
What an amazing build and an even more amazing history that led you to this point. The model looks fantastic. Your father would be proud indeed ! Can't wait to see the completed model.
 
Cheers,
Joe

Vivian,
 
I have just started from the beginning and read all through your log. Very very nice looking ship ! Well Done !! I have never built something from this period, but now seeing your wonderful looking model, I am rather interested ! I really love the finish you achieved as well. Another thing that I have really enjoyed with your log is the way you approach the project and the joy it brings you that you have so beautifully shared here. Thank you.
 
-Joe

There are many ways to approach weathering...... Typically I will work all of the finish coats of a painted subject in something solvent based. This way I can go back over later with washes or highlighting in water based paints.... As for using the pastel chalks, which I love, they need something to grab, so a good coat of 'flat' airbrushed on, then use the ground pastel chalks. As has been noted, you can use the ground pastel chalk mixed into a medium...be it paint or thinned glue to create much heavier textures....this can be used for built up mud, rust, algae, etc.....
 
You must be delicate when sealing these with the final spray of gloss or semi-gloss as it tends to 'mute' the effect somewhat.....experiment and you will soon develop a technique that you like. A local craft or art store usually has the large box selection with a broad range of colors for a reasonable price, and the chalk sticks will last a very long time if only used as weathering agents !