Starship Modeler Discussion Forums

Carbon refers to carbon steel. This is cheap and brittle. You want HSS drill bits (High Speed Steel). You should be able to find a tool merchant who will sell you a small pack of ten rather than buying them singularly. Try Dormer as a brand or Hertel.

It does, of course, depend on what your file is clogged with. You can also heat files in a flame to melt/burn out crud (not so hot that you destroy the temper of the file) or simply file a piece of mild steel edge on.

Use a small butane torch or gas ring to heat the file. This will burn the crud out but don't get it too hot or you'll alter the temper of the file. You should then be able to brush the remains out. For really stubborn dirt, try filing a piece of mild steel 'edge on' to remove the accumulated crud.

If you have a look in the 'Finishing' section, there's at least one sticky thread and several related threads.

We mix aluminium powder into polyester (fibreglass) laminating resin all the time. Normally polyester isn't ideal for casting but mixed with aluminium powder in a ratio of roughly one part resin to three parts powder gives a mix that can be brushed on like a gel coat or cast without excessive shrink...

Bouyancy is a product of volume x density, i.e. the larger the volume of the bubble, the greater the weight of the heavier liquid material it is displacing and the more the bubble is being compelled to rise. If you want bubbles to rise in resin or rubber, put the mix in a vacuum chambers so that eve...

I think there's some confusion over the term backing boards. I'm referring to two part moulds being squeezed together by the use of two rigid boards either side as per Blappy's photo in the second post and the original question. I think Sparky is referring to laying a piece of flat silicone on top o...

I've used backing boards on larger molds that wont fit into a small pot and that works fine but haven't tried anything under pressure using backing boards only 1 part open face molds. Sorry, a bit more science. It sounds like you're working under a misconception. The mould will be no more likely to...

If it's the 'Liquid Nails' we get in the UK (white in colour), it's just PVA wood adhesive but twice the price. The name is simply useless marketing speak.

It goes without saying that everyone has checked their printer for accuracy? I don't mean the resolution quality but the dimensional accuracy. Scan and then print a piece of graph paper and then compare the original with the copy. It might surprise a few. If you want to check if any error comes from...

If it's going on wet, it's not an air pressure issue. As Migmaker suggests, it's more likely a compatibility problem. You could ask the manufacturer of the pearlescents what primer they recommend.

3cm (28.6mm = 1 1/8") thick should be perfect for that size.

Don't be tempted to underestimate the forces involved. If you're using a pukka high vacuum pump, if the lid breaks, it will go with one hell of a bang.

All I know is that it works. I don't care how.

Nice to see the future of the human race hasn't lost it's thirst for knowledge. Sigh!

I think what makes the compressed bubbles rise easier might be more simple, the smaller volume of the bubble means a smaller point is trying to push through a viscous material. Sorry but again, the physicist in me tells me I don't think that's right. If that were the case, the smaller bubbles would...

Compressed air bubbles are very buoyant, this is way scuba divers must where several pounds of lead weight, to make them neutrally buoyant. So compressed air bubble will float to the surface of a mold even faster when compressed. (Emphasis added) Sorry but I don't believe that's true based on simpl...

Try a firmer rubber too.

Thanks. The question was actually aimed at Chas but run by me again how a pressure pot makes bubbles move to the surface?

Hold for 5 minutes , then decompress. All the expanding air moves to the surface.

Hasn't the resin set or at least thickened by then?

Well we called it a robot. Essentially the upper chamber contained two bowls of approx. 2.5L volume, both on pivot rods. One was above the other and over to the right, the other held a mixing paddle attached to a motor. Below these ... SNIP ..that were wrapped in duct-tape in the cambers. We knew t...

How did you manage to manipulate the mixed resin to pour it while it was still in the chamber?

So I read, (on a decal instruction sheet, of all places), that putting enamels over lacquers is asking for trouble. No, that's OK. Lacquers over enamels is bad. As a rule of thumb, the paints with the most aggressive thinners go on first and should not be used to overcoat weaker paints. Enamels sho...

Carve a pattern and vacform it.

Actually, this was a technique used by the Anderson model makers in the early sixties. Drawing panel lines on with a pencil was one thing but you can get another effect to show weeping joints. Scribble some pencil lead near the edge of a sheet of paper. Offer the edge of the sheet of paper up to the...

Technically, blow moulding is done inside a rigid two part mould. It's like inflating a hot plastic balloon inside a hollow mould then splitting the mould open when it's cooled. Vac forming over a male mould means the surface of the pattern doesn't have to be brilliantly finished since the surface a...

Plastruct do two solvents. One is water thin and usually comes in a can, the other usually comes in a bottle and is a tad thicker, best described as having the consistency of milk (but still clear). The former tends to penetrate joints better. Sounds like the glue isn't penetrating the joint. Also P...

Stainless steel would be more expensive and has a tendency to work harden depending on what grade it is. If you PM what you have in mind, I might be able to advise. How thick is this part? I have two VMC machines.

Not sure if this applies to the unit pictured but on a conventional former, if the plastic sheet leaks air around the edges because the sealing strip is failing, you can put sticky tape around the edge of the sheet to make an air tight seal before putting the clamp in place.

Be wary of using anything that contains water (like some clays) when vacuum degassing particularly if you have an efficient vacuum pump. Lowering the pressure can cause the water in the clay to boil particularly when it's warm and that will obviously create bubbles.

.040" or forty thou is 1mm or so close as makes no odds.

.060 is 1.5mm which is as good as 1/16th"

therefore 0.8mm is 1/32nd" and 0.4mm is 1/64th".

If the plastic is drooping under it's own weight, that's more than hot enough. If you're not getting the plastic to pull into the detail, you may have to drill tiny evacuation holes to allow the trapped air out. While applying the vacuum, you can also heat local areas with a hot air gun to keep the ...