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Jan 31, 2013, 09:58 PM
Entropy is happening!
Jim.Thompson's Avatar
What is "tooling board?".

Sorry for all the basic questions.
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Jan 31, 2013, 10:53 PM
registered user
It's a tool that's bored ?
Feb 01, 2013, 12:37 AM
I am actually really slow
Tooling board is a polyurathane material thats commonly used to make moulds from. It comes in a wide range of densities each with different properties. Its usually pretty expensive though because it's hard to find in small quantities.

Been talking to Sean about making new joiner moulds from an aluminium filled resin casting. Should be able to take alot more pressure and temperature then the tooling board moulds he has now
Feb 01, 2013, 12:40 AM
Everything's A Compromise
Larrikin's Avatar
Re tooling board, I mean no disrespect, Jim but Google is a great resource for finding out about stuff.
This is just one site in WA that sells different types of TB.

In 2000, I had the pleasure of billeting Jens Buchert and Martin Weberschock for about 1.5 weeks. They left me with a sample of TB620 from Advanced Composites

They used the TB620 for milling the plugs from which they then made epoxy moulds. They may have changed their process since then but the sample has been put to great use as a sanding block. Light weight, rock hard and completely flat.

Feb 01, 2013, 05:32 AM
Can you DS it??
spotterone's Avatar
After reading about the Pull Saws on here, I had to have one!

I dropped into a Masters Hardware store and found them in their saw section. They are branded Tajima Japan Pull 265. Thats the link to them at the Masters website.

I just tried it on a bit of 4mm G10 sheet, and the G10 munched the teeth on it. I also tried the 19TPI blade, and it munched that one too. Quite a few of the teeth are missing now, but even with the missing teeth, it seems to cut plywood pretty well so all is not lost.

It might work on a thicker section, but not much chop on the thin stuff.
Feb 01, 2013, 06:52 PM
608 km/h!
josh18's Avatar
Thats pretty sad to hear, Mine is the same one I think. Ill have to watch what I cut with it.
Feb 01, 2013, 06:54 PM
Can you DS it??
spotterone's Avatar
Originally Posted by josh18
Thats pretty sad to hear, Mine is the same one I think. Ill have to watch what I cut with it.
After cutting the timber with it, I reckon that they are pretty good saws, it's just that they aren't designed to cut thin stuff. I broke the cardinal rule of minimum 3 teeth touching at any one time, so it's my own fault anyway.
Feb 01, 2013, 06:59 PM
608 km/h!
josh18's Avatar
Ahh I see. I still reckon it would eat a carbon joiner for breakfast.
Feb 01, 2013, 11:13 PM
It flies!
Sean Moloney's Avatar
Great to hear Masters carry the pull saws, thanks for the tip Leo.

I cut the ends off the joiner, tried a fine toothed handsaw and a hacksaw. The hacksaw cut through it a little better, and much easier than I would have thought. AvB is right not much harder to cut than timber which is a surprise for such a chunky piece of carbon. I can really see the value of a drop saw though just to get a perfectly square cut.

The wingtip plugs got their final paint coats on Thursday and I spent a large part of yesterday levelling the still soft paint with 600. They're looking really nice now, very straight and smooth, can't wait to see them polished. I'll leave the final sanding/polishing for a few days to let the paint completely gas off to minimise any shrinkback of the polished surface. Two of the four plugs are in the hotbox right now at 45deg C, so they might even be ready for the final sand/polish tomorrow....
Feb 01, 2013, 11:26 PM
Auzzie built planks
timbuck's Avatar
Looking great Sean. At this rate I'll be chucking one off cactus in a few months. .

Latest blog entry: More colours
Feb 02, 2013, 12:55 AM
It flies!
Sean Moloney's Avatar
Fingers crossed!!!!!
Feb 02, 2013, 09:58 AM
less sleep more planes
PlayinInTheParK's Avatar
Its good to hear that you are happy with the progress ,touching a big piece of wood when typing .
Feb 02, 2013, 09:24 PM
Everything's A Compromise
Larrikin's Avatar
The Sniper build is flooding back to me. Keep your eyes on the prize. It's gunna be a hellava unit.
Feb 06, 2013, 01:04 AM
It flies!
Sean Moloney's Avatar
I remember reading about the mammoth sanding and polishing effort you did on the Sniper David. Absolutely beautiful work, and I find it amazing how often I've thought back to your Sniper thread for guidance and inspiration while working on this project.
Feb 06, 2013, 01:58 AM
It flies!
Sean Moloney's Avatar
Some progress - two of the four wing tip plugs have been finish sanded and polished. They came up very nicely but definitely not flawless. They look beautiful in the pics but there is some paint shrink back and a couple of minor blems that only show up under fluoros. This has always been the case for me when sanding/polishing two pack so I'm not at all surprised. It could be that these blems won't show up on finished parts but I have a suspicion they will, so I think a polishable tooling coat will be required to get the kind of mould surface I've been aiming for.

The sanding and polishing went quite well. A few notes on how i went about it:

Sanding blocks: (see pic) I mostly used square section aluminium to level the paint with the coarser grades. I found these hard blocks necessary to avoid rounding the corners at the TE, wing root, joiner and parting planes. For the finer grades (1200-2000) I used a hard foam block bought from the local auto paint supplier. This worked really nicely. A few different sizes were used for different areas. Surface was kept very wet while sanding using a spray bottle and plain water. 600 was used to level followed by 800, 1200, 1500 then 2000. The paper was glued to the block with spray adhesive which grips well enough to use almost instantly. I have personally found that wrapping paper around a block causes folds at the block edges that can scratch your surface and round off corners (eg TE on these plugs).

Sandpaper: This might be obvious to some reading this but it's quite new to me - sandpaper ain't sandpaper. I learned this while making the stabiliser plug but had a reminder of this while working on these plugs. I've been using a brand that my local paint supplier recomends - "Siawat". It's noticably thicker than cheaper stuff and has a really silky feel to the cutting side. While working on one plug I ran out of this brand of paper in 1000 grit and reverted to some cheap stuff bought from Supacheap Auto. The difference was surprising, you could feel the scratchiness of the cheap paper as it cut vs the silkiness of the good paper. This cheap paper left some deep scratches that had to be fixed with the good stuff. I'm told that cheaper papers can have rogue coarse grits in them.

Guide Coats: These are another revelation having only recently learnt about them. I didn't find it necessary to use a guide coat for the inital levelling - you can easily see the areas that need sanding because they're still glossy. But for the intermediate finer sanding they are invaluable and hard to imagine doing an even job without them. I found it necessary to use acrylic sprayed from a gun to get a fine enough guide coat. Spray cans didn't produce a fine enough mist and it seems when using spray cans you spend more time sanding off the blobs of acrylic rather than the plug surface. It is a bit of a pain having to mix paint and the then clean the spray gun but it is well worth it for the results. Less guide coat is better than more but I still found I was tending to put on a little too much.

Cutting compound. I tried a new cutting compound for the final buffing. It worked really well! My local paint supplier recommended it over Farecla, which I'd used previously and was supposedly the duck's guts up to now. This stuff - "Q Cut" seemed to cut quicker than the Farecla, gave at least as good a finish and is slightly cheaper to boot, but certainly not cheap by any standards! Thankfully you don't need to use very much. I used an electric buffer with a hard (orange) foam pad to begin with followed up by a softer (black) foam pad. The square edges around the wing root and joiner ate the hard foam pad for breakfast but did nothing to the softer pad. Myself and my workshop were covered in foam chunks/cutting compound by the end of the day!

Cleaning the cutting compound off the finished plugs almost took longer than buffing them. It gets stuck in the troughs and takes quite an effort to remove. You have to be very careful wiping the plugs before the cutting compound is completely removed because it can scratch the paint. It would be great to take the plugs outside and hose them down but I don't think it would be wise to risk getting moisture into the MDF, even though that seems unlikely now the plugs are well sealed.

So, getting closer every day. There are two more wing tip plugs to finish sand/buff then it's time to make some moulds!
Last edited by Sean Moloney; Feb 06, 2013 at 02:04 AM.

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