IanW's 'Corroded Cat'

Joined: 5:14 PM - Apr 18, 2015

9:35 AM - Apr 12, 2018 #1

Airfix 1/72 Consolidated Catalina PBY

This project was triggered by something I found whilst researching the Truk Bay rescue project.

I found a photo of the 'ground crew' of a Catalina wading out up to their waists in icy water to the aircraft and thought it might make an interesting diorama as Airfix do a Catalina kit.

Had a look round the dealers at the next show and could only find a recent boxing for £24.99. Was chatting to Colin about the idea at the Stoke show and he said he had at least one in his stash and would see what he had.

Turns out he had one of the started/incomplete kits donated by Pat of Collectakit, and most of the parts seemed to be present so this will be the subject.

The kit has been started (very badly) with some unknown form of glue which seems not to have fixed the parts together but appears to be somewhat difficult to remove.





Although Colin thought most of the mains parts were present, a careful check shows some fairly vital parts are missing, although it might be possible to make replacements. Main problem is that the props are missing though I migh be able to find something similar in the parts bin.

First task was to have a go at removing some of the worst of the glue.

Tried soaking a minor part in Caustic Soda without success. Tried carefully applying cellulose thinners to the glue - it did seem to soften the glue slightly but this method runs the risk of damaging the plastic.

Where the glue was relativly thick I found that a really sharp blade can be inserted between the glue and the plastic and the glue prised off.


Although the glue does not adhere well to the plastic it seems the solvent in the glue has produced some pitting to the plastic - which is a shame.



Given the glue problem I am beginning to think that it might not be feasible to continue with the orginal plan.

I do however have a 'Plan B' - which is based on the observation that 'Ian's Rusty Wrecks' seem to generate quite a lot of interest at the shows, so why not try something similar for an aircraft. I found several images of discarded Catalinas such as this one and think it might be an interesting challenge to to try and depict a salt corroded airframe.
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Joined: 5:14 PM - Apr 18, 2015

1:44 PM - Apr 25, 2018 #2

Having spent some time trying to remove more of the surplus glue, I have come to the conclusion to go with Plan B and turn this into a 'Corroded Cat'.

The main reason for this is that there are one or two quite prominent damaged areas on the visible upper surfaces and although it might be possible to fill the damaged areas they will still show up, as the rivetted panel detail will be lost.









The damage to these areas will be utilised to depict some of the ultra corroded areas evident in the photos I have found.

One thing that surprised me when I trial assembled the mainframe was just how big this aircraft is and hence how big a base I will need.

I managed to find a suitable large picture frame in the 'frame stash' (I tend to pick up assorted frames for future bases from local charity shops when available).

As the plastic in this kit is quite thick, and I want to try and depict the outer skin of the airframe with areas of corroded aluminium, I have spent quite a lot of time of the last couple of weeks trying to thin the plastic down in areas.

Tried using various grinding/sanding tools in the modelling drill to remove the inner surface - the main problem with this method is that it can be very easy to overheat and melt the plastic and it is not easy to get a consistent thinned down 'skin' effect.



Found the best(safest) method to get the required effect is to scrape the inner surface of the plastic down using an assortment of home made scraper blades, made from old modelling knife blades and sections of old hacksaw blades with the ends shaped using a carborundum cutting disc in the modelling drill.



This is however quite a slow laborious process but it is possible to thin the plastic down to quite a thin layer without damaging the surface detail except where it is desired to produce areas where the panels have corroded away. This shot with a light behind the wing panel shows how I judge where to scrape next.



To try and reduce the volume of the storage box required for transporting the finished article I decided to try and 'collapse' the wing mounting pylon - not sure quite where this avenue is going at present.





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Joined: 11:55 AM - Mar 29, 2015

2:49 PM - Apr 25, 2018 #3

An interesting project Ian.
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Joined: 5:14 PM - Apr 18, 2015

5:31 PM - Apr 25, 2018 #4

Not sure how long it will take - the more I look at it the more complicated it could get.

The photos of the real derelict airframes highlight a glaring error in the Airfix kit, which depicts the whole of the wing structures as metal skinned, whereas the actual plane had the rear 1/3 fabric covered, which of course soon rotted away, leaving just the framework, although this does seem to have corroded away in most of the photos.
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Joined: 11:55 AM - Mar 29, 2015

8:04 PM - Apr 26, 2018 #5

Think of it as practice for the other Beaufighter dio you have been musing about with the exposed spars and ribs.
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Joined: 5:14 PM - Apr 18, 2015

7:41 AM - Sep 05, 2018 #6

About time I updated this thread, given that the lst post was in April.

Have been doing occasional work on it over the last few months, but there has been a tendancy to lose enthusiasm as I find that the more I do the more I find I need to do to achieve the desired goal.  The long hot summer has also been somewhat of a deterent as my work room tends to get quite warm.

Marked out the areas that need to be removed from the rear edge of the wing panels and carefully cut them off, only cutting the plastic from the inside face of the plastic to try and avoid damaging any surface detail.

It is a slow process to scrape down the rather thick plastic of the kit, the aim being to depict individual panels on the wings as having been corroded away, as in many of the photos of long abandoned Cats I found on the web.
In order to try to make this look realistic, the plastic needs to be thinned down to almost fag-paper thickness, after which the corroded parts of the panels can be pricked/cut out as required.

As these aircraft had quite a substantial wing area, there is quite a lot of plastic to be removed, which is quite tedious and rather messy, the workbench and floor, not to mention my clothing, tending to get a generous coating of thin shavings of white plastic.

On the real thing the rear edge of the panelled portion of the wings consists of a bulkhead/spar with  very visible cross-bracing.  To depict this I added a sheet of thin plasticard with ribs from 0.25 * 0.50 mm strip.  Again a slow process - only one outer wing panel having been done so far.

Having thinned down the wing panels, before removing the corroded sections I added some internal ribs from thin plastic strip.  These help to strengthen the very thin plastic and also give a represention of the internal wing structure, especaily at the outer end of the wings, where the drop-down float supports are situated.
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