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Found 8 results

  1. Hello, While working on my YF-105A (over on W.I.P.), I managed to misplace the canopy. After checking my two backup kits, only one kit had the canopy! As these kits are rather hard to come by (Revellogram F-105D) these days, I decided to explore my options. First I check around, looking for a vacuform canopy for the 1/72 F-105D. Nada, which is not surprising, considering the "ear flaps" and thinness of the original. Next, I looked for resin canopies. I found a really great one, but only in 1/32nd scale, and after all, we modelers must maintain some sense of propriety and not stray from The One True Scale! The one I found in that scale was however, a beauty, from the F-105B correction kit, from the former Meteor Productions, Inc or Cutting Edge F-105B correction kit, as sold by Mr Dave Klauss: This is a beautifully rendered masterpiece, and if I could buy one in my scale, I would! But, since I can't, I thought to study the work of the masters. Closer examination of the molder pieces (only the clear ones here, not trying to replicate the kit!) revealed that The molded bases or resin reservoirs, as they are in real life, are both slightly tapered toward the canopy parts, and the corners of the bases are cut off. This serves to aid in removal of the part from the mold after casting, and may save even a little resin, a concern more having to do with mass production, rather than the one-offs that I'm trying to do. Secondly, and hard to see in the front main canopy, are the small bits added between the base and the canopy to provide clearance and material for sawing the finished canopy from the base as shown better below: In my rough and tumble proof-of-concept effort effort here I have used a chunk of old pressboard for the base piece, but I have added some 10 thou card between the base and the part, for the afore-mentioned reasons. All these were glued together with RS watch cement, as CA glues have bad effects on some resins and some silicone rubber. In the background is a box made of Lego blocks, on part of a Lego base that I cut to the size needed. One can make the box from all sorts of things, but some kinds of plastic have the advantage that the silicone rubber won't stick to them. The large piece of scrap blue silicone is there only to hold the main canopy at the correct angle while the glue dries. You will note that in the first photo, additional material (denoted by the hatch lines) had been added when the master was made, to enable the cast part to be pulled straight out of the mold, while my first effort was left at an angle. Eventually my masters were stuck onto a thin layer of clay that provides the bottom of the box, as well as sealing the lower edges of the box, to avoid silicone leaking out of the mold. It should be noted that regular modelling clay won't do here, as the process requires sulfur free clay, or bad things happen! For this casting effort, I'll be using the Amazing Clear Cast clear resin, which my bottles are around 2 - 3 years old, and OoMoo25, which is brand new. Both of these were procured from Amazon. The Oomoo 25 was properly mixed 1:1, and poured into the mold box, with the masters in place. I took no special effort about bubbles because, I use pressure casting as a rule. For those interested, I have provided a link to my set-up, and would be happy to answer any questions about it: Ed's Poor Mans Pressure/Vacuum Casting Pot The silicone was poured into the mold bob and allowed to set under 55lbs pressure, for 75 minutes: Above right, after the Oomoo had set up, the masters were removed, and I was ready for a casting try. You will note the total absence of bubbles, due to the pressure casting. I then mixed up the resin and poured it into the mold, and allowed it to set under 55 lbs pressure for 48 hours, as per the resin directions. When that time was up, I attempted to de-mold the resin canopy pieces, and then ran into the problem: First off, the resin is kind of yellow. I believe this is due solely to the age of the bottles. Normally, resin has a shelf life of 3 - 6 months, maybe more with a little care, like nitrogen shot into the opened bottles, to keep oxygen and especially any moisture, from getting to the resin, even in a re-sealed bottle. Second, the parts were still tacky and flexible, not hard. This could also be due to the age of the resin, but it could be that perhaps I shout have pre-cured the silicone mold in the oven at 150 degrees or so for a few hours. This time, etc, vary by manufacturer and product. Since I had used this very resin a couple of years ago with Oomoo 30 (which only varies in setup time) I didn't consider this. Another factor is that the molding is very thin. Castings less that 1/8" or so are problematic for many resins, many also requiring a post cure period in the oven to achieve maximum strength and durability. I will investigate some of these issues in my next attempt. Since the resin was still soft, I managed to scratch this piece getting it out of the mold, and totally destroyed the windscreen part! I was however, encouraged by the fact the that the thin wall section was able to be reproduced by the pressure casting method, and the detail was all faithfully seen, and given the old resin, still had good clarity. After three days out of the mold, the casting is still hardening, but slowly. I have ordered another brand of clear resin, and some 3/8 clear acrylic sheet for the base part. I will take everything I have learned from this effort, and make a second attempt. Please stay tuned if interested, as it will take a few days for this all to be done, as well as more time in the mold and pre and/or post curing time. You will kindly note again, the absence of any bubbles, due to the pressure casting! I would dearly love to know the brand of the resin and silicone that Dave Klaus used for his pieces, if anyone out there happens to know, or any useful suggestions from others who have tried this process. I'm certain I will succeed, just not sure how long it will take! Back ASAP, Ed
  2. Has anybod used "Blue stuff" to make any spare parts and if so how did you get on. I have bought some but only 4 sticks I think you would need the 8 stick pack to do anthing of any size Website here Youtube video here on how to use it Will be interested to see what others think Rodders
  3. GazB

    Wheel Replication

    I'm considering trying to replicate wheels for an older HEMTT kit I have (the Tanker, which doesn't seem to exist anywhere anymore). I currently have a set of resin ones I'm using on another M977, but these are actually too small in diameter to be entirely correct. Since the DEF wheels I was looking at were both expensive and snapped up almost instantly, I've looked into the possibility of creating moulds of the tyres and hubs from the Italeri M1120, which I also have. I've never done casting before so I'm a little unsure as to the process. I don't really have the ability to buy all of those pressure components and stuff, but I've been looking at this product: http://www.greenstuffworld.com/en/inicio/545-silicone-putty-300gr.html Been wondering what would be easy stuff to pour into it, and what the best way to cast these wheels would be. I've considered assembly of the tyres and hubs, then making three moulds for each of the types. Its how to position the wheels in the mould that I'm wondering about. A single piece mould would provide the best result but, trying to get the wheel out again (I considered adding a small stick to create a channel) is something I'm not sure about. A two piece mould could work but, I don't know how I could pour a liquid into both and get a good result ultimately. Any advice on this would be much appreciated Gaz
  4. Before I built the modified pressure pot described elsewhere in this forum, I built this very cheap (for me) vacuum chamber for de-gassing silicone and resin. I started with a simple insulated ice bucket, double- walled aluminum, around 10" diameter and 9" high. For some reason, the plastic lid had gone missing. Then, I added a simple sheet of silicone, designed to be used by bakers to line a nine-inch pie pan for non-stick purposes. I cut a large hole out of the center to admit the vacuum and to observe the proceedings. Any material could be used as a seal, that won't admit air -- sponge, probably not. Lastly, on E-bay, I obtained a sheet of Lexan about 1/2" thick, drilled a hole in the center (not very straight), and threaded the hole with a tap sized to fit the vac hose fitting I installed. I sealed it with liquid rubber, as of the type you can dip tool handles into, or use for painting insulation onto electrical wiring. A few coats were needed to stop the leaks. Then, I added an old hand-held vacuum pump tester/brake bleeder combo, that I already had ($15 - $30) online depending upon quality. The whole rig is shown below: I can pull 22 -26 inches of mercury with this, depending upon how hard I want to work. Takes a while, but is a cheap solution if a vacuum chamber is all you need. Ed
  5. There is very useful information on-line about converting 2-1/2 gallon paint pressure pots on-line. One you-tube video shows this in great detail, while a .PDF shows combining pressure and vacuum into one pot, requiring two gauges and a vacuum pump. I like to find the cheapest, simplest way to do the job, so without further ado, here is my poor(er) man's option. I began with scrounging up an old mechanic's or HVAC hand pressure gauge set. Since most of the modern world has gone to expensive, fancy machines to cature freon, these gauge sets are readily available. They are distinguished by having a low-side gauge, which reads both vacuum and pressure (up to 12o PSI), and a high-side gauge, which reads pressure only, usually up to 300PSI. They may be configured for either R-12 freon, R-134a freon, or whatever is current in the HVAC field. Doesn't matter which you use, as all you will need are the low-side gauge, the hose, and the appropriate fitting for the vacuum pump end of the hose. I had an old set laying about that was already broken. The high-side gauge had been broken off, but the rest was intact. After removing the hose, and the low-side gauge, it looked like this: The low-side gauge looks like the next photo where the "P" and "V" refer to the pressure and vacuum reading parts, respectively. The next thing required is a vacuum pump. Usually, the recommendation is either a purpose-designed pump or a recycled refrigerator pump. Since I also had a cheapie (read about $29.00) automotive venturi-type pump, I used that. The photo below shows mine, where the hose from an air compressor comes in (about 100 PSI needed), and shows the odd-ball adapter I added, so I could use the pump with either R-12 or the later R-134a type car setups. If you use one of these, it doesn't matter, as long as you can adapt your hose from the pressure pot to the pump. The fellow on-line that offers the PDF file gutted his pump, and just hooked up the guts. That was a little to exposed to damage for me, plus I already had the hose and fittings, so I went that route. I suggest you due a search on-line and then go your own way. The next photo shows my hook-up to the pressure-pot's lid: The next photo shows some of the mods to the pressure pots, that are pretty much the same for everybody, given I only use one gauge. Of note are the 1/4 turn air shut-off valves, red for the vacuum side and yellow for the air pressure side. These coors are not significant, and only ended up because I got the valves at two different places, and one had a female end where the other had a male end, and they ended up in these positions solely because of the brass fitting I had laying around. I did have to buy a couple, and they are available at automotive stores or big-box or hardware stores. Also shown below is the T-handle for the pressure regulator. The pot supports 60 PSI. I set the regulator shown here at 50 (AFTER setting the pressure relief valve, shown later to 55 PSI). Below is another view of the pressure pot lid: All joints are sealed with three wraps of teflon tape. The "T" fitting under the regulator was actually supplied on the pot as a piece of cast pot metal or some-such, and it gave me fits trying to get it to stop leaking. I finally replaced it with a brass fitting. A WORD OF CAUTION HERE!: Before doing ANY mods to your pressure pot (should you try one!), Follow the instructions, put it together and then pressure test it up to 60 PSI and see whether it will hold the pressure for an hour or so. Get yourself a real bottle of leak detector fluid from your plumbing supply stockist. Do not rely on the dish soap and water mix, as it is NOT sensitive enough. The right stuff will show you tiny leaks, by exhibiting dozens of really tiny bubbles, a half-hour after you apply it, if any leaks exist. Regular soap mix will fool you into thinking you are leak-proof, even if you aren't. You may feel free to ask how I know this... In any event, if you cannot seal the factory-provided parts prior to your modifying the pot, take it back, and exchange it for another! I got my pot off E-bay for $33.00 plus shipping, when the pot usually goes for around $100.00 new from Harbor Freight, so I figured that there would be some problems. I had to replace some fittings, chase the threads in the lid itself, and replace the original lid gasket, so I ended up being in it for around $80.00 all up. If you sign up on the Harbor Freight website, they will eventually send you a coupon worth $20.00 off a $100.00 purchase. Since they also sell the quarter-turn valves cheaply, pop for a couple and -- Bob is somehow related again. The fellow who has the you-tube video suggests cutting a wooden disc out of 3/4" ply to make up for the fact that the bottom of the pressure pot is NOT flat. Below, is my quickie answer, a piece of 3/4" lumber cut to length. I will probably do a proper circle covered with some resin-shedding product eventually. I also added a plastic 4 or 5 quart plastic ice-cream container to catch resin burps, etc. Below is a look at the whole shebang, put together. BTW, tighten the lid clamps as tight as you possibly can! Below is a picture of the compressor I use to drive this pot. It is kept in my garage, and normally used for putting air into tires or driving nails or other housely things. It replaced a larger, old one I had for driving air tools and such years back, that finally gave up the ghost. Also, please be aware that your airbrush compressor will not drive this rig, unless it's pretty awesome. I set the regulator on the output end of this compressor to 60 PSI, when used for casting. I usually use this rig as follows: I make the mold masters in one of the time-honored traditional ways, the I mix the RTV rubber in a larger cup than needed. I put the rather violently-stirred mix into the pot, shut off the pressure intake side, and then plug the compressor onto the venturi vacuum pump. I can pull between 24-26 inches of mercury with this setup (anything over 20 is fine). When the vac hits 20+, I shut off the vac side also and turn off the venturi pump. I give it 2-3 minutes under vacuum, then pull the relief plug to release the vacuum (semi-slowly). When the gauge reads zero, I open the pot and pour the degassed mixed silicone into the molds. I then put the molds into the pots. Unless they are somewhat large, I do not use vacuum at this stage, but if the molds are larger or have adequate pour stubs to contain the resin, I might use vac before pressure (perhaps 2 minutes). For the rockets and gun barrels, I used none -- just pressure. If I have used pressure, I simply shut off the vacuum side while holding the vacuum, re-attach the air hose to the pressure side of the pot, and start up the pressure -- again, without releasing the vacuum, if used. I then wait until the pressure pot hits 50 PSI, and then walk away for the needed time for the resin to cure, Then, I'll return, shut off the pressure side, and pull the relief valve to De-pressurize the pot and remove the castings. The air compressor will turn on and run if needed due to tiny air loss, to maintain the needed pressure. The last photo shows some of other folk's resin masters that I test the rig with. There are 1/72 rockets and machine gun barrels, and a Hasegawa B-26C turret sprue. The 20mm tailgun turret in the center is my master. I have cast resin in various ways for many years, and this is the first time I have ever gotten perfect casts, all the time. Any minor problems I have had are all resulting from improper mold design. One last thing I neglected to mention. I so far have used OOMOO 30 silicone and Micro Mark's CR-900 resin, mostly because of longer pot times (15-30 minutes). This gives me time to do all the de-gassing, but are not suitable for production work. The CR-900 however, has one very useful feature -- that tiny molding, like the rockets and gun barrels become very hard and strong AFTER SEVERAL DAYS. This stuff is great for super thin castings, but you could probably do better for thicker stuff. Thanks for tuning in. Comments, suggestions or outright attacks always welcome. Ed
  6. Its called the 3Doodler.It "writes" on things and fresh air!You can build with it.It uses ABS plastic.A thin rod of ABS is fed through the barrel of the pen and heated to melting point.A cooling fan near the nib dries the ABS instantly.Watch the video on the link below.You can fill gaps, draw thin lines of ABS plastic.It costs $75.Looks like a really useful tool. http://hexus.net/tech/news/peripherals/51861-3doodler-75-3d-pen-hits-kickstarter/
  7. About 15 years ago I wrote a book about mold making and resin casting which was based on my apprenticeship with a master mold maker and from experiences I had while operating a resin model kit manufacturing company back in the 1990s (Wingnut International). The book was self published and rather hard to get, being a completely "in house" operation--I printed, bound and sold the book directly to my customers. It was a modest success but as is the nature with many books, sales gradually dwindled until it was no longer worth my time and effort to keep it in print. The book attained sort of a legendary status and there have been inquiries from time to time about the possibility of reviving it. This wasn't an easy thing to do because the ancient software used to make the book was incompatible with more modern hardware and operating systems. Then about a year ago, after being lobbied hard for the rights to the book by someone active in the how-to publishing field, I decided to take another look at the feasibility of bringing it back into print. I did a literature search and discovered that no book published since has gone into the detail mine does, so I began to think that maybe it would be worth the effort to revive it for the 21st Century. I've spent the last year updating the book and working with an editor to improve it and make it compatible with modern distribution channels. The book is now professionally printed and bound and available on CreateSpace.com, a division of Amazon.com The book is also now available on Amazon and Amazon UK. Copy and paste Secrets of Expert Mold Making & Resin Casting into the Amazon search window and it will take you right to the listing. If 2 listings show up, go to the one with the blue/green cover--the white cover is for the old edition and is no longer available. I have been trying to get Amazon to remove the old listing, but no luck yet. Sorry for any confusion.
  8. Twenty hours or so after I filled the base of my vacformed Dalek with casting resin I found a small area where the plastic had softened to something a bit like stiff chewing gum: It more or less elastically recovers: I don't know the resin chemistry but it is one of those clear embedding types, I got it from Hobby Craft and filled it with some powdered filler and black weathering powder. It only appears to have affected a small area about 1 by 2cm. Has anyone seen anything like this? Will the plastic reharden or is there anything I can proactively do about it like putting it in a low oven, exposing to UV light, nuclear radiation, etc.?
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