Trimming plywood parts

[Michael Rogers]

Hi Everyone

I'm building a Trouper 12. Slow progress so far, because as a diversion I had to give priority to going into hospital 3 1/2 weeks ago to have some internal bits removed. That has all gone extremely well, and I am now only held back by rather low energy and stamina levels, a temporary state of affairs which is improving daily. All that by way of explaining why I am still at square one, cutting out the parts from the ply sheets. As several of you are galloping ahead, and doubtless several more have 'been there, done that" in the past, I thought I would take the liberty of benefitting if possible from your collective experience.

My instructions for cutting out include a sketch showing a saw, wielded in cuts right through the ply sheet, to cut short full-thickness 'securing tabs' at intervals to release the parts; minimal final trimming involved My ply sheets have the parts marked out differently, by a partial thickness routed groove right round each part, every inch of which has to be sawn. The grooves are 6 mm wide, and I haven't attempted precise and definitive cuts with the saw, especially round sharp corners. This means that all the parts will need careful (and laborious!) trimming away of remnants of partial thickness ply sheet, in order to achieve their precise shape (which I must say is extremely accurately and sharply marked out by the routing process).

Has anyone else had to do this? If so, any tips about the best tool(s) to use for the trimming? I thought I would try Surforms, either the small flat 'plane' or the trimmer with the orange handle and short rockered blade, or both. There might, I suppose, be a useful Microplane tool. Bright ideas, if possible based on practical experience, would be very much appreciated please.


(SP Cadenza, and Trouper-in-build)

[Anthony Huggett]

I used a Bosch jigsaw to cut out the panels, leaving a small amount of the thin ply on the wanted parts, then 80 grit sandpaper (green stuff on a roll from Wickes) and a block. It does take time, and I went round the edges with 120 grit before coating each panel in epoxy. The alternative is to cut too close with the jigsaw which might be quicker but may mean you lose the shape in places where it is crucial, particularly the hull parts.

I found the plywood box containing most of the small parts very useful as a table for supporting the plywood whilst cutting. There are some pics in my BR17 build thread.

Regards,

Anthony

[Clem Freeman]

jigsaw for me, then stanley knife/small hand plane/spokeshave and a final sand. I cut all mine out first but some parts have twisted whilst being stored so not sure whether it would have been better to cut them out as required.

[Michael Rogers]

Thanks, guys.

For some reason I think I was scared of doing something daft on the cutting out. Anyway, fortified by your encouragement, I got to work with my jigsaw, and then for the final trim I tried one of the tools I mentioned. It's called (rather confusingly?) the Surform Shaver: mine has an orange plastic handle (they've changed it to yellow) and a short slightly convex blade, and it 'cuts' on the pull. And, for this particular job it is BRILLIANT! I could trim off all the unwanted ply both quickly and accurately, with a finish which will scarcely need sanding.

So, if you've got any more cutting/trimming to do, or for anyone who reads this before setting out on cutting out their ply parts, GET ONE. They're about £2-75, spare blades £1-50: an absolute bargain - cost you less than a roll of sandpaper.