Paddleducks
Paddler Modelling => Construction => Topic started by: djcf on August 16, 2009, 05:48:10 AM
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Hi all,
For a model I am building, I am using thin wall brass tube (1/4 inch dia) for portholes, was thinking of trying EM400PA clear casting resin to simulate the glass, from
trylon.co.uk
has anyone used this stuff, or any other suggestions for a waterproof clear material to simulate the glass?
Clark
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Hi Clark,
I have used Polylite 32032 supplied by Allscot in Glasgow.
I used the same method 1/4inch tube filled with resin.
Long story short - it wasn't worth the effort or cost IMO - see pic bellow.
In such small amounts it either took a very long time to go off or didn't go off.
For portholes above the waterline i now use a good sized 'blob' of Canopy glue with a coat of clear enamel on the outside effect equally as good as the resin and a lot quicker / cheaper.
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I use it (EM400PA) and find it's perfect - if a bit expensive.
What I do is cut out the bits of brass tube and clean them up a bit, put them in a tray made from clear polycarbonate (?) the blister packs you get things like rail stanchions in are perfect (as the resin won't stick to it) and put a bit of resin in each to seal them. Then, when it 'jellies' fill them almost to the top. Once that is no longer runny, fill them to a sort of 'dome' and stick a piece of polycarbonate on the top, displacing the extra resin. After about 2 days depending on the temperature they're ready to have all the excess resin chipped/sanded off the outsides and be used in the model...
edit; forgot to resize the pictures!
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I do find it only works with EM400PA which is designed for use in very small castings, ordinary clear casting resin doesn't set properly (I think you need a kind of 'critical mass' of the stuff for the chemical reaction to take place!) I also find that no matter how careful I try to be, about 1 in 10 get air bubbles in them and are no use - so make a few more than you need...
...Oh yes, also, it shrinks a bit as it sets and mine always end up a bit concave, using multiple thin layers would overcome that but I get impatient and include one really thick layer.....
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...once fitted I think they look pretty good (even though I over did it with the rivets!)
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Thanks guys, thats really helpful advice. Kim, I'd heard about the canopy glue method also, but what attracted me to the EM400PA was the fact that several of my ports are not only close to water level, but there is a short rubbing strip (belting) on a section the hull, at the waterline, which I assume will throw up water onto the ports when sailing.
Also, as Mick says the casting resin sets in small quantities, dont want it to stay tacky!!
Mick, the ports on your model look great....I'd be well happy with that ;D
Clark
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Well , I have casted some ports using EM400PA, & I must say I'm happy with the results. I used a bit of glass as a base for the ports rather than polycarbonate...the ports come away ok. As Mick says, it does shrink very slightly leaving the top a tiny bit concave, but I have been using the bottom of the casting as the outer face, so the resin is flat & only 1 or 2 with bubbles. Will see how the next batch turns out!!
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I have used the brass tube method, but I fill the tube with clear bath silicone. I also fix the tube with silicone as my model had lots of portholes at water level. It's cheap, and can be removed and smoothed when still wet with white spirit on a cloth or small stick. R.G.Y.
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Mick
where can I get this stuff? I like your method a lot and the results look good. Do you know if it's postable - or is it highly inflammable/toxic?
info gratefully received!
Stuart
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Hi Stuart,
EM400PA resin & catalyst
http://trylon.co.uk/
I got it by post in UK, don't think they will post it overseas...Not sure if there are any regulations regarding that or not.
Let us know how you get on
Clark
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Hi Fitz
I'm too lazy to cut up brass tube when I make portholes.
I use brass olives from compression pipe fittings from a plumbers merchants (they are sold separately) and I fill them with clear cast resin from my local craft shop which is used for making clear paper weights.
I put them on plastic and like you, I use the flat bottom as the outside when attached to the hull. Sandy
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Mick
where can I get this stuff? I like your method a lot and the results look good. Do you know if it's postable - or is it highly inflammable/toxic?
info gratefully received!
Stuart
I get it here - http://www.modelshop.co.uk/ - I go there and pick it up though, quite possibly they'd post it. It's no more harmful than ordinary car repair resin/GRP kits, not sure what the rules are in this age of security/safety consciousness about sending chemicals through the post...
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Hi Fitz
I'm too lazy to cut up brass tube when I make portholes.
I use brass olives from compression pipe fittings from a plumbers merchants (they are sold separately) and I fill them with clear cast resin from my local craft shop which is used for making clear paper weights.
I put them on plastic and like you, I use the flat bottom as the outside when attached to the hull. Sandy
Good idea with the olives Sandy, will have a look for them in the future. Cutting & cleaning up the brass tube is a chore, but I needed two sizes and 1/4" & 7/32" tube was just right this time. Maybe even do the ports for the next model when I'm on a roll ;D
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Thanks for that guys - I'll make some enquiries.
Stuart