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[Korp1010]

Hi all


I'm currently building an OTW Upholder submarine and need to purchase some plastic to make the Water tight cylinder supports and various other items but would like some suggestions on the best type to use, I was thinking either Styrene, ABS or Perspex but not sure which would be best suited as it's obviously going to get wet and needs to be epoxied to the GRP hull.


Advice welcome


Matt

[Subculture]

Any of those will work. Best stuff IMO is glassfibre sheet, as it's really tough, and bonds well into a glass hull. e.g.

https://www.hobbyplastic.co.uk/index.php?main_page=index&cPath=52_54&zenid=d7vf0tsdfqktlqj5mh3s683tr7

Use a good slow cure epoxy (no 5 minute stuff) e.g. Araldite precision or JB weld marine, or even better are modified acrylics, although they tend to have a swifter cure time, so you have to work a bit faster.

[derekwarner]

Matt..........if you are after small sized sheets....a Hobby Shop if you can find one will have both Styrene and ABS....

ABS has the advantages of rigidity, easy to cut and drill, end sections can heavily abraded/ring-drilled for keying into an epoxy bond against a GRP surface with a similar surface preparation

Styrene has less rigidity, Perspex is marginally more difficult to saw, sand & drill over ABS...Perspex also has very sharp edges and can shatter...many people use a tape mask on cutting lines to minimise chattered edges with Perspex

Perspex joints could be achieved in a similar process to ABS, Styrene always has the shiny greasy surface finish....and with the lower rigidity joints could be an issue

Considering the application, ABS would appear to have the advantage............last point, ABS has a relatively low melting point and will display a melted edge if used with a high pressure  or force against a belt or disk sander

Derek 

[Korp1010]

Thanks for the replies, never thought of glass fibre sheet so will look in to that.

Thanks for the glue advice I always use either 24 hour Araldite or my favourite is UHU Endfest 300 which is also 24Hours set time.


Derek as you mention I was worried styrene would not have the strength required on it's own and perspex although strong can crack and shatter like you say so ABS seems to be the best choice but I have heard that it can absorb water over time is this something to be concerned about as it will be painted over anyway?



Matt

[Subculture]

I think some over theorizing here. Not sure what cylinder you're using, but if it's an OTW, what do you think that is made of?

[Korp1010]

Hi Subculture


Possibly over thinking it but just trying to get the build right first time as it's a lovely kit.


It is the OTW cylinder i'm using which is made from Acrylic I think.

[derekwarner]

Matt......,.sorry  , being an above water person I did not realise that ABS in fact does an absorption affinity rate over time with water

Even if the tank supports were painted, over time a minute crack could occur and the absorption process  commences

[I once made 2 x stern tube bushes from something from the Family of Nylon.........& being immersed a few hours per week, they grew but as they were constrained externally, the material seized on the 0.250" propeller shaft]...

I don't think you are being over cautious ......just logical .....so some more research required........... Derek