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So the new year starts with some scratch/ kit bashing building practice, i want to build one of the Revell tugboats into a flying Sci-fi junk boat but that is going to take a lot of building that i need A LOT of practice in. So this a practice project, its a deep space probe/ship/satellite with a hint of retro and Ma.k. influence. Starting point is a yakult bottle. Had a go at using milliput as well, i will be using a lot more of this. Fitted the nose and what will become sensor domes, these will be filled in and shaped with milliput once the resin glue is dry. You can see my box of plastic bit for building into stuff!
Making photo etched parts at home Many years ago I was a young apprentice in a small electronics company, one of my tasks was making printed circuit boards (PCBs) for prototypes and one off’s. Making PE parts is a very similar process, so I gave it a go. When I made PCBs the boards were pre-coated and we used ferric chloride as an etchant, I’m going to show you how to make a double sided PE using dry film resist. You will need to invest in some bits and bobs to help you along, nearly everything is on good old ebay, the rest you can get in Tesco, ASDA etc, and don’t forget to pick up some wooden or plastic stirrers from Mc Donald’s and the like. I won’t write a long list now of things you need I’ll leave that to the end and get straight to the interesting bits, You may not get success first time but keep practising, I had many fails at various stages getting this right so i'll share what I know. but first this :- Making photo etched parts uses some hazardous chemicals and as such safety steps should be taken in the form of protective clothing, gloves, goggles etc. The chemicals are corrosive to skin as well as to brass so should be immediately washed off with plenty of water if contact with skin occurs, medical attention may be required as well. By continuing to read this article you must accept that YOU are responsible for your own safety and should read all labels and safety data sheets available. Nuff said, lets get on with it. Artwork The artwork was printed on over head projector (OHP) film for inkjets this film has a rough and a smooth side. The rough side is the printing side. We are going to use negative resist film so when you create your artwork white is where you want brass and black is where it is to be etched away. You will notice the ‘sprue gates’ are only on the rear art work this is so they get etched away from one side only and become half the thickness off the surrounding brass. Start off by creating your artwork without the gates so the parts are ‘floating’ with no attachment to the surrounding frame, save this file call it ‘front’ or something now make a copy of that file and call it ‘rear’. Open the rear file into your editing software and draw the ‘gates’ in. You now have 2 files front and rear. Print your files using your printers best settings, on mine I have selected Print quality high, Use black ink only, darkness max, contrast max, high resolution paper. If your software can print alignment/crop marks, use them! If not add some crosshairs to your art work but they must be the same on both files so check for this before you create the second file. The two artworks are shown here, top is the front with the floating parts bottom is the rear with the 'sprue gates' (to be printed mirror image) Fold lines should be on the inside of the fold and twice the thickness of the brass. Printing preference page manual ajustment pop up page Because I’m from up north and a bit tight, to save on OHP film print off one of your artworks on plain paper first, now you can cut out a bit of OHP film appropriate to the size of your artwork to include the alignment marks, tape this to the paper over where it is to print and put it back through the printer, same again with the other file. Print the rear one as a mirror image and let them dry for an hour or so. I’ve tried using laser printers for the artwork but the blacks aren't as deep, I find the inkjet better. We have 2 artworks, the rear one should be turned upside onto a white surface or light box if you have one. Cut the top art work out so it just includes the alignment marks but make sure it smaller than the bottom one. Now carefully align the two together on top of each other with printed sides on the outside, this is where your alignment mark come into use, use a magnifying glass if necessary. When you are satisfied that you cannot get aligned any better put a piece of tape across one edge to form a hinge and make sure it doesn't move as you do so. We now have our art work prepared, did you make that second check that is defiantly aligned? If it has moved peel off the tape and do it again, super accuracy is required here if your PE is going to be of any use. Cut out a piece of brass just bigger than the artwork with scissors and give it a clean with Acetone, IPA or other solvent. I'm going to use a 0.005" or 0.125mm gauge sheet Applying the resist The resist is a negative resist so the bits that get exposed to UV cure and harden while the unexposed bits stay weak, the resist should be stored in the dark and away from sunlight. It should also be kept away from sunlight and bright lights while your work with it until it has been developed. Switch the laminator on. Cut out two pieces of resist just larger than the brass, the resist is in between 2 protective sheets you need to remove one before applying to the brass. Take one piece and with two bits of tape on either side of one corner pull them apart, one of the protective sheets should come away, you might find it takes a couple of goes to get this. Put your brass on something flat that will be easy to turn around as you work, a hotel room key is ideal for this, make sure there is no dust or anything and put a big blob of water on it. Take your piece of resist, find the side without the protective layer (it’s the side that feels sticky if you touch it on the edge, don’t touch the bit that’s going on the brass) and gently offer this side to the brass, when it touches the water, the water will grab it, gently lower it on and let it settle. Check there are no air bubbles trapped, if there are just lift the resist a little and gently give the bubble a little persuasion to depart. You might need a little more water before lowering the resist down again. When you’re happy that there is nothing there except a thin layer of water give the centre of the sheet a small press just to tack it into place and stop it slipping, then with a tissue or soft cloth work the water out from the centre don’t press hard just yet, if you do it will tack that bit onto the brass making it harder to remove should you find an air bubble. Once you are happy that you have ALL the water out with NO air or water bubbles trapped smooth the resist down with a bit of pressure. Take a piece of paper and fold it in half, gently lift the brass off using a scalpel blade to break the adhesion and place it in your folded paper. The paper acts as a carrier to go through the laminator if you put the brass through naked it will get bent and damaged, also as its small it might get lost in there, with all the electrical hazards you might expect with a loose bit of metal rattling inside an electrical appliance. Once though the laminator, open up the paper, the resist will be stuck to the brass except where there is air or water trapped, you did get it all out didn’t you? The overlap will also be stuck to the paper so take your scalpel and cut the brass sheet free. Do the same for the other side. Exposure You need a UV light source, ebay has some ladies gel nail curing lights for £10-15, they come with four bulbs two above and one on each side, you only want the light going straight down through the artwork onto the brass so leave the side bulbs out and put them some ware safe, these are now your spares. You need two sheets of glass, I found two cheap 4”x6” photo frames the ones that are just glass and wooden back in Tesco for 50p each kept the glass a threw the rest away. Make sure they are clean, now slip your brass between the two artworks making sure you are happy with the positioning then sandwich this between the sheets of glass and clip together with bulldog clips. A quick check that the brass is still in the right place, no foreign objects obscuring things and the handles of the clips are not in the way. -Optional- You get a slightly sharper image if you remove the protective sheets at this stage however you run the risk of the resist getting stuck to the artwork if this happens you will need to strip the resist off the brass and start again. This is why the artwork has been prepared printed side out. If you get the resist on the artwork IPA or acetone may get it off (only clean the non-printed side) but you could end up having to print a new artwork. Expose this to UV light, I have a bit of cardboard clipped to the side not being exposed, this is just to stop light spilling round to the rear so you can remain in control of how much exposure takes place. Once exposed turn over, swap the card to the other side and expose the other side. Timing, getting the timing tight is critical, too short and your resist is not suitably hardened, to long and you start to expose the bits you shouldn't, remember the artwork is actually translucent the black bits don’t block the light completely they just attenuate it. I have found 45 seconds per side seems to be the optimum timing, this will all depend on how dark your black is, how strong the light is, how close the bulb is, how old the bulb is. 45 second is for my setup yours may differ, some experimenting maybe required. Once done your brass should have the image on it with the exposed bits turning darker blue. Edit - You can use sunlight to expose but be careful as this is an unknown and variable quantity so you could end up over exposing it. Developing As I said earlier exposure to UV light hardens the resist leaving the unexposed areas soft and dissolvable in the ‘developing’ fluid. The fluid we are going to use is a sodium hydroxide solution. Sodium hydroxide is caustic soda sold as household drain cleaner. We need to make a 5% solution of this. I’m going to make 50ml of the stuff. 1ml of water weighs 1 gram so 5% of 50g is 2.5g. you need to make enough to submerge the brass in your container, find out how much you need either in volume (ml) or measure the weight of the water (g) and multiply this figure by 0.05 e.g. 50g x 0.05 = 2.5g. This is how much caustic soda you need to weigh out. Dissolve this in your measured amount of warm water. You’ve now made your developing fluid. Be careful, this is corrosive and will cause chemical burns. I warm the fluid up by leaving the it in the airing cupboard where it is 38°c, Remove the protective layers from your brass with tape on the corner, once the protection is removed avoid putting the brass flat down on any surface, if you do the unexposed bits may well stick to it and you will be back to stripping and starting again. Dunk you brass in the fluid for 2-3 min to dissolve the unexposed resist, you will see it dissolving and turning opaque or milky. Then wash the resist away under a running tap, you can assist this by gently brushing it off with an old paintbrush under the tap. Have a really good look to see if you got all the resist off look carefully as it can be difficult to see. If there is any left put it back in the solution for another minute and wash off again. Don’t leave it in for too long however as it may start to dissolve the exposed stuff too. Once your satisfied you have got it all off put it back under the UV to see if you missed anything, if you did, strip the brass with acetone (see stripping at the end) and start again. Pain in the neck I know, but you haven’t yet etched it so you can reuse the brass. Better to find out now rather than once you've etched it in my opinion. Etching To etch we are going to use an acid to erode away the brass. Sodium persulphate is an etchant used in making PCBs, other etchants are available including ferric chloride, ammonium persulphate & potassium persulphate. For sodium persuphate a 20% solution is needed so multiply your weight/volume of water require by 0.2, so for 50ml of etchant weigh out 10g of sodium persulphate. I haven’t tried other etchants yet, so other ones may need different concentrations. This is also highly corrosive and will cause chemical burns. Find a suitable non metallic container and stirrer and dissolve the etchant in the appropriate amount of water in the same way as you made the developer, and warm it up for use, for me that’s put it back in the airing cupboard again. (It may take a few minutes of stirring to fully dissolve.) Submerge the brass in the etchant, as the etchant tends to become more concentrated at the bottom give it a stir every 10 mins or so until fully etched. The pic shows pin holes starting to appear after 28mins and after 50mins it was fully etched. Keep an eye on it. I nearly over etched this one as I was writing this article at the time. Don’t forget the areas that are going to be etched from one side only will carry on being etched until it is washed off and also the etchant will start to undercut from the sides. So as soon as you are satisfied that it is fully done. Remove it from etchant and fully rinse it under a tap. The etching time will increase as the etchant becomes exhausted the more times you use it, the same will happen with your developer. Stripping Soak the PE in acetone for a few minutes to remove the resist, it should start to peel of but might need a little help. The acetone will become purple in colour and becomes a fantastic dye so watch you don’t spill it, I have a bottle I keep the used acetone in just for cleaning PE. The photo actually shows it in water and is just for illustration! If all is well you've just made your first PE, go have a beer or three to celebrate. Things you need Brass http://www.ebay.co.u...=item5d304537b0 Dry film http://www.ebay.co.uk/sch/i.html?_odkw=dry+film&_osacat=0&_trksid=p2045573.m570.l1313.TR0.TRC0.Xdry+film+photoresist&_nkw=dry+film+photoresist&_sacat=0&_from=R40 OHP film http://www.ebay.co.uk/sch/i.html?_sacat=0&_from=R40&_nkw=inkjet+ohp+film&_sop=15 UV Light http://www.ebay.co.uk/sch/i.html?_trksid=p2050601.m570.l1311.R1.TR10.TRC0.A0.Xuv+na&_nkw=uv+nail+lamp&_sacat=0&_from=R40 Sodium hydroxide, caustic soda cleaning product section of ASDA Tesco etc Glass sheets - cheap photo frame Spatula http://www.ebay.co.uk/sch/i.html?_sacat=0&_nkw=laboratory+spatula&_frs=1 Etchant Different types are available - Sodium persulphate, ferric chloride, ammonium persulphate & potassium persulphate. Couldnt find the Sodium persulphate I used doesnt seem to be listed, http://www.ebay.co.uk/sch/i.html?_odkw=pcb+etchant&_osacat=0&_from=R40&_trksid=p2045573.m570.l1313.TR0.TRC0.Xetchant&_nkw=etchant&_sacat=0 Edit 28/8/13 Looks like the Sodium persulphate is listed on ebay again http://www.ebay.co.uk/sch/i.html?_trksid=p2047675.m570.l1313.TR0.TRC0.Xsodium+persulphate&_nkw=sodium+persulphate&_sacat=0&_from=R40 Containers, I used lab beakers, do a search on Borosilicate beaker Scales, search pocket scales or micro weighing scales Stirrers grab a hand full at McDonald’s Timings & quantity's Exposure 45sec per side 1ml of water weighs 1gram Developer 5% strength 2-3mins at 38°C Etchant 20%strength 45min to 1:30 at 38°C (Sodium persulphate) Single side etch To make a single side etch, still apply resist to both sides of the brass and expose the rear completely. etching time will be double as the etchant can only eat through the brass from one side so has twice as much go through to meet the other side. I'll make updates to this as I find new things but in the meantime good luck! Mark
Hi, and happy new year 2014 to all Britmodellers. I've decided to bin everything I previously did on my Sanger Shackleton and start again more seriously (and I hope more successfully). I chose the same path as Tom did on his superb build, and started with the engine nacelles, with quite an ambition: I intend to make a master and cast four "power eggs" in resin. I can't back out, as I already spoke of that point to two gentlemen who told me they were interested in two sets each. Well, now I have to deliver. So here's what I've done so far. John Aero told me the front end of the engine nacelle basically was a Spitfire Griffon nose with an annular radiator (I oversimplify, but that's the idea), so I took a Daco Spitfire XIV nose, removed the rocker covers and glued it to the front part Sanger provides: Then I figured the radiator usind .01 solder wire: The center grid is done using fine mesh a French friend provided (he's interested in a set too, so...), The walls of the nacelle were thickened at the opening using bits of plastic cards glued then puttied. The front part is almost done. The picture is merciless: looking at it, I saw the problem with the two "wings" on each side of the resin part. I'll correct it this evening. Now with the nacelle parts: Have you seen errors I overlooked? Please tell me, I want to correct any mistake I've made before closing the nacelle. TIA, Sebastien
Hi all! First just to say a quick hi to everybody! This is actually my first post and my first model in a really long long time, actually it's my first armour kit. The model in question is an old issue of a Panzer Ausf. V G 1/48 from Academy, which is a motorized version. Although I am not planning in focussing much on the motor bit. I got this model back when I was a kid so I had to go through undoing a big gluey mess I did back then. As I am using this model to learn all the techniques back again I would much appreciate comments on how to improve things! As you see I cleaned the side objects there were glued to the sides of the hull and have started adding Miliput plaster for the Zimmerit cover. I have made a custom mould for the zimmerit pattern out of plasticard with a scribbler. I have also added some brass mesh to the air intakes at the back to the tank. Here is a detail of the zimmerit pattern: And here from the back of the tank: As you see there is still plenty of fitting issues at the back of the hull and also on the front. Here is a detail of the front: Also as you can see I have started adding some plasticard to the sides as I plan to add some scratch-built armour plates to the side. This is it for now. I plan on keep on adding the zimmerit and give it a light sanding. Also finish adding the armour side plates and modify the upper bit of the turret where the gun joints to give it the proper shape of the Ausf. G. I was also thinking in adding the curled protection plates to the exhaust at the back of the tank. Thanks in advance for your comments! All the best, Alex
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.