The Toro method

[AdmiralDonSnider]

While this eastern approach to manufacturing round stars (as well as burst compositions) has been already treated in several existing threads, it has certainly not received the degree of attention it would deserve. I take this opportunity to open a thread dedicated to the Toro method solely, its theory, strenghts and weaknesses, the experiences made with it.

 

For me personally this is a new field. While I have gained experience with the western approach to rolling stars (one amateurs might be familiar with particularly due to the publications of Dave Bleser) and have had good success, the japanese/oriental "Toro method" is becoming a topic of growing interest, particularly because it promises to overcome some of the drawbacks of "dry rolling" stars.

 

I know several people here are using the Toro method in an amateur environment (industrially it seems to be the method of choice anyway) and I would greatly appreciate it if they shared their findings.

 

 

It is only the wish to provide a basis for our discussion to build upon that makes me stress some informations taken mainly from Shimizu (FAST pp. 185ff). According to him the toro method is a way to produce round stars by means of repeated and alternating applications of slurry (made from the star composition to be pasted) and dry compositon in powder form, followed by completely drying the stars and starting over.

The success of the process relies on heavy cores i.e. cut stars, small pumped stars or round cores previously grown using an atomizer and it seems to be a method which is - at its best - suited to large (and heavy) batches (which is also the case with the western approach, an aspect often overlooked by beginners). It does not seem to work well with cores as small and light as seeds or sand grains, which tend to cohere to each other and are best grown with an atomizer.

Cut stars, which according to Shimizu show high end brightness and good burn speed - characteristics both desirable in warimono type shells - become round after several applications of composition. After repeating the growth cycle several times, the stars are set to dry - in the sun! to prevent the solvent from soaking into the core. Well dried and cooled stars are then enlarged further, a process which can be repeated several times a day given good drying conditions (weather).The speed of growth varies with the kind of compositon.

 

The Toro method is suitable for both hand and machine rolling, using either single (or double) rolling pans or mechanized rollers. In either case it requires a good deal of experience and a feel for the optimum viscosity of the slurry, which unfortunately varies with the size and amount of stars to be coated as well as with the individual composition. Under optimum conditions the bottom of the pan is clean. SGRS seems to be a superior binder, as the dried stars do not soften as easily as with dextrin when they are moistened again. This may serve as a starting point.

 

 

The Toro method obviously has its drawbacks, but also a lot of advantages compared to common "spray bottle" rolling. Some drawbacks that come to my mind are e.g. the necessity of frequent drying as well as the masterful art and considerable effort required to determine the exact viscosity and make up the slurry.

Advantages are obviously very uniform, hard and smooth stars, with the practical elimination of any "spiking" phenomenon. The wetting is even and results in even stars (selective screening is still necessary). The stars remain soft during rolling, which helps even out any sort of bump. Color changing stars are easily produced and reliable "changing" primes are easily composed by altering the inner and outer composition in the wet-dry cycle. These seem to be only a few of the very promising advantages pointed out by someone unfamiliar with the method.

[pyrojig]

I too have given this much thought after frustrating learning curves of atomized "dry" rolling . It seems that the technique has to be changed to suite the type of comp to be coated. While some comps roll with ease, others are a real pain. I like the concept of the toro method and have been reluctant to try due to the lack of detailed info out there on this subject. In my reading, I recall that the coating of cut stars is the most common for the torro method. If your starting out with the dry method, at the point that your just out of the finicky stage and ready for the torro, they are starting to grow very fast with the dry method ( so why not stick with it). I would love to hear from folks that have a handle on this practice. I believe that it may prove to provide a way to grow masses of stars very fast. This too may be of use for the screen-slicing stars or moose-turd's, as a starting point as well.

[Mumbles]

I only have experience with priming stars with this method. I typically do this by hand. I haven't tried in a roller, but from what I've encountered, the process is probably a little different. When priming I use a 1:1 mix of composition and solvent. This comes out somewhere around the consistency of gravy or perhaps cold oil. This mixture works for me for both BP and water or 4% gum arabic solution, or Pinball prime and water or alcohol.

 

I typically just make this mixture in the bottom of an ice cream bucket or 5 gallon bucket depending on batch size. I apply layers in 5% increments. That is if I have a kilo of stars I apply the prime in 50g increments. 50g of prime and around 50mL of water/alcohol. The slurry is made in the bottom of the bucket. I add the dry prime and add the solvent all at once, and stir it around with my hand or a spoon or whatever I feel like at the moment. Once the slurry is formed I add the stars and stir them around until they're all equally coated, I mix in the dry powder in a few increments. It will normally take up about an equal mass, so 50g additional prime. I just add it until the stars are free tumbling and the slurry seems to be fully "saturated" with dry powder. The final consistency is about like that of a freshly rolled star or cut star. It's soft and can be scraped off, but it's pretty well consolidated and adhered. I typically will only do a maximum of 2 layers at a time before drying, though stick to 1 layer if I'm not in a time crunch. With a drying box, which I'd imagine is not all that dissimilar to an ideal drying day, it takes about an hour to dry if it's bound with alcohol and about 3-4 hours with water. These are probably overkill, but I like knowing it's totally dry. Without a drying box I usually give it about 12-24hr. I especially like knowing that a layer is totally dry if I am switching solvents.

 

For priming easy things, this is generally just 1-2 layers of green mix and I'm done typically making sure the powder addition leaves very dusty stars or using some component of coarser powder. For harder to light things, I use 1 layer of pinball slurry and pinball powder. The second layer is pinball slurry with green meal powder for sort of a step prime. Then I finish with a layer of green meal slurry and powder. For very hard to light stars, or things I need to be 100% positive light, I use a slurry of star composition with pinball prime powder, then go about the previously described priming. This is generally unnecessary though. If a star fails to light, it's usually because of the outer layer, or perhaps the pinball prime blowing out.

[spitfire]

I am not sure if i can contribute valuable info. I worked with the toro method a few times, in a star mill. First thing i encountered it indeed works best with large batches, like 1kg or up. Small amounts only make a big wet mess of your batch especially when one is starting with small material. Advantages are fast working, even coating and fairly consistent size of growth, and very little (if at all) airborne dust. For multiple layers drying is essential. I even dry the stars completely before adding the prime layer. For now i am not even close to mastering this technique but the first few tries where very promising! It is definitely worth a try. Start with one color stars, red, green, purple, blue, etc... The method asks for a lot of tweaking when it comes to the slurry and adding ratios of slurry/dry powder. Try it. There is a reason why pro's use this method.

[enanthate]

"Toro" is as simple as adding water/alc to the starcomp, making it a slurry?

How much slurry/dry comp? 50/50?