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Author Topic: Hollowing out top block.  (Read 1078 times)

Online John Rist

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Hollowing out top block.
« on: January 02, 2022, 03:41:20 PM »
Is there any neat tricks to hollowing out a top/bottom blocks of an 59 Ares? What is the best way to get them thin to save weight but no so thin you punch a hole or create a week spot?    D>K
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Online John Rist

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Re: Hollowing out top block.
« Reply #1 on: January 02, 2022, 04:13:39 PM »
A lot of work, but it is done. Also I have two forms for making 1/8th inch  molded shells for the Ares. Lighter and quicker.  H^^I can bring them over for you to look at.
Great.  Bring them to the GLC meeting this Monday.   y1   #^  I will probably stick with the carved blocks of wood.  Don't want to get into fiber glass molding at this time.
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Offline Tim Wescott

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Re: Hollowing out top block.
« Reply #2 on: January 02, 2022, 04:17:13 PM »
I've only done molding once.  I just followed Bob Hunt's instructions, and even with the effort of making the forms I think it was less work than carving.

If you do need to carve a block, hold it up to a strong light (or hold a strong flashlight up to the back of it).  You can gauge how thick the material is how much light shines through.  You probably want to compare with some pieces of scrap, to get an eye for the shine vs. thickness.

Use the tool of your choice -- I used a home-made gouge, by looking at some carving tools on the web, taking a piece of 3/16" music wire, and cutting away anything that didn't look like a gouge.  It works really well, but I have to sharpen it all the time because music wire isn't exactly knife steel.

Sane people will :
  • Buy some carving tools from a reputable woodworking shop (and be sure you know how to sharpen them, because balsa dulls sharp edges like nothing, even with good steel)
  • Buy an xActo gouge set (assuming you still can???).  I'd buy extra blades, because sharp is good.
  • Use a Dremel tool.  I tend to shy away from using power tools for things like this, because they go faster than I can think -- with hand tools I can stay ahead of my impatient incompetence; I can't always do that with power tools.

The last time I carved a block, rather than doing what the plans said and leaving things flat where the fuselage formers came up, I just gouged out a great big dugout canoe, then fitted formers into it.  It seemed to work well, and it sure took me less time.
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Offline Tim Wescott

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Re: Hollowing out top block.
« Reply #3 on: January 02, 2022, 04:17:42 PM »
Great.  Bring them to the GLC meeting this Monday.   y1   #^  I will probably stick with the carved blocks of wood.  Don't want to get into fiber glass molding at this time.

I think Ty is talking about molded balsa -- I certainly was.
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Offline Ken Culbertson

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Re: Hollowing out top block.
« Reply #4 on: January 02, 2022, 06:05:03 PM »
  • Buy an xActo gouge set (assuming you still can???).  I'd buy extra blades, because sharp is good.
You will find them in the buggy whip section.  Hobby suppliers are flat out and they have been discontinued by E-Xacto.
BUT, if you look close and sneek up on the web sites, some are still out there.

https://www.tools4flooring.com/winkelman-wdd-745-trimming-blades-4-pack.html

These are the best tools made for carving blocks.  These may not be X-Acto but who cares.
Price is as low as I have seen.  Carving blocks is a great stress relaxer.  I learned to keep one at work to reset my brain.
Got that from one of our sport's departed elder statesmen.

Ken
« Last Edit: January 02, 2022, 07:50:37 PM by Ken Culbertson »
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Offline Dennis Toth

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Re: Hollowing out top block.
« Reply #5 on: January 02, 2022, 07:32:34 PM »
John,
If you have carved, shaped and sanded the blocks you could use them as a form to mold 1/16" sheet around. The technic is pretty easy, get a large ACE bandage, next take some aluminum foil and cover the form. Trim off around the bottom, now you can remove the foil and open it up to give a pattern for the balsa sheet. Trim the wood leaving 1/8" ish around the edges. Now if possible use "A" grain wood (B grain will also work), heated with a MonoKote heat gun. To mold around the form tape one edge to the bottom and start heating the wood down its length, as it warms start to form it around the block. As you get to the top you may need to heat it a bit more to get it to form smoothly. Once you have it around the form you can tape the second edge to the bottom, then take the ACE bandage, heat the wood once more, and wrap bandage, with a medium stretch, around the wood and form and let it sit overnight. Some like to soak the wood in a water/ammonia mix, use a paper towel to dry it so it is just damp then wrapping around the form and put on the ACE bandage. If you use the water it many take a full day or so to dry and set. Some do two layers of 1/16" with a light smear of epoxy between them.

Best,     DennisT

Online John Rist

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Re: Hollowing out top block.
« Reply #6 on: January 03, 2022, 09:32:17 AM »
John, I am refering to molding balsa over the forms. Very quick compared to a block. As to the block, first carve it to the outside dimensions, then do the hollowing. I have a complete set of carving tools you can use. H^^
OK!  The molded method sounds good.   See you at the meeting tonight.
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