Tuesday, March 10, 2009

Spray Rails

Originally uploaded by Phil_Parker
Regular readers will have noticed a lack of updates on the Brede Lifeboat project. My excuse is that I've been busy doing other things but to be honest a seemingly insolvable problem hasn't helped.

The spray rails at the front of the prototype boat are very prominent. To replicate them I hoped to pick up some triangular section plastic, stick this to the hull and then sand it to the final profile. Trouble is, you can't buy triangular plastic or wood of sufficient size. The largest I could get was from the Plastistuct range, but at 3.2mm high it was too small. This problem stumped me. I tried sanding some square section wood to shape but couldn't do this with sufficient accuracy to satisfy my critical eye. Holding such a small bit of tree is nearly impossible while manipulating a sanding tool.

In desperation I decided to try forming the rails on the hull itself. The Proxon sander gave me confidence that this might work and all that messing around with the hull last month proved that it could take a little bit of attack without damage.

The start and end points of the rails were carefully marked on the hull with pencil and then strips of obechi were soaked in the sink to maker them pliable enough to deal with the required curves. After about 20 minutes each was dried off and then stuck in place with superglue and clamps. This dried off really quickly and despite the undulations the wood appeared to be firmly fixed.

The wood was too large but gentle work with the detail sander soon fixed this. All work was carried out by eye. Looking along the hull it was quickly apparent when one side was fatter or less tapered than the other. To achieve the final shape I carved the bottom corners off with a sharp knife and then finished off with the mini sander.

sprayrail2Looking at photos I have probably under-represented the rails which look pretty chunky but they are close to those on the plan and if you aren't sure about a part making it under scale isn't a bad idea. More importantly they look right on the model.

A couple of coats of sanding sealer later the wood is nice and smooth just needing a coat of primer to check everything is OK and hide the shiny bits. then I can breath a sigh of relief and move on to fitting the mechanical bits.

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