shaping minicell...

[truckeeboater]

What's the best/preferred tool(s) for cutting and shaping minicell foam? My initial forays have included: a sharp bread knife (hack job!), a dull hacksaw blade (better, but too flimsy for bigger cuts), and varying degrees of sandpaper (50 grit to 120 grit). Also, how smooth should two surfaces be before applying adhesive to ensure a strong bond?

Thanks!

[Atucky]

also get a sure form tool

http://www.stanleytools.com/default.asp ... %3B+Shaver" onclick="window.open(this.href);return false;

[watermonkey]

Band saws are nice if you have access to them when cutting larger chunks off a bun. I used a table saw for the same purpose as I didn't have access to a band saw. Result were marginal, kickback and grab made for excitement. Electric filet knives have their uses for some contours. 80 grit flap wheel on an angle grinder or 80 grit belt on belt sander make the foam fly and you can get good contours using both. I finally ordered some dragon skin on line as I couldn't find it anywhere - I thought it sucked at shaping. Sure form is better than the dragon skin. I have graduated to my second can of weldwood. When I started, my foam looked pretty and I was meticulous in my shaping...now I just want the boat to fit and have chunks of random foam glued in all over the place. Esthetics not on top of priority list anymore.

[Larry Horne]

yeah, running soft foam through a table saw is a great method... to loose a few fingers. 30 years of full time carpentry experience speaking here..DON'T DO IT!

before i got a band saw i used a jig saw a lot. you can get a pretty long blade for them, it makes a better cut than a knife, and it's not very sketchy unless your trying to hold onto too small of a peice (those of you with garbage bags full of foam bits know what I'm talking about).
hand saws work ok too.

The two surfaces don't need to be smooth. being flat helps, but it is foam afer all, and it squishes together pretty good if you glue it right.

[clt_capt]

Band saw is definitely the cleanest way to go if you have access. If not a hacksaw blade is not bad... Just rough out the line, then sand - shurform or dragon skin are preferred...

[truckeeboater]

thanks for all the help, guys! Heading down the hill to Home Depot tomorrow to get me one of those sureform tools.

[kmcinturff]

Here is how I do it for what it is worth. Note that I do not have a bandsaw.

A super sharp, large blade filet knife and a metal straight edge. I have used this to cut pretty big pieces of foam, and I've even made my own saddles from scratch.

To shape, I use a Stanley sureform shaver (as mentioned above), dragon skin (for rounding corners), and I recently bought from Lowes a Kobalt brand metal file (can't remember the model) that has a REALLY rough texture and it does a pretty good job as well.

Here is another secret: to remove large areas of foam while keeping the surface as one plane, you can take a sharp hand miter saw (the metal saws that you typically use with the small, wooden miter boxes), and use the surface of the saw blade as you would a piece of sandpaper. Be VERY careful as this will remove mass quantities of foam very quickly. I used this method when I made panels to glue to my inside walls of my prelude to match the contours of the hull. This will obviously leave lines in the foam where each blade tooth goes across. Follow up with Stanley shave to smooth up.

[hammerhead]

Heavy duty fillet knive and Sureform tool does the trick.

[hazardharry]

got this from nrs http://youtu.be/ecIViobVP-A" onclick="window.open(this.href);return false;

[truckeeboater]

^^ we've got a few of those around the rafting office, use em mostly for scoring patch material for rafts, but I guess they would work just as well for foam. It seems like a smaller version of the Stanley tool described earlier. What is the Dragonskin product some folks are talking about? Like a super-rough sandpaper?

[Shep]

dragonskin is a thin piece of metal with lots of holes poked in it. It works like sand paper, but it works better on minicell. Doesn't clog up. Very effective. Leaves a nice surface finish.

http://www.amazon.com/Harmony-Dragonski ... B0047H45DK" onclick="window.open(this.href);return false;

[jakke]

Rather cheap and good cutting: black and decker recipro saw. Any recipro saw would do actually. B&D actually provides a blade that is just a tad short.

[Mike W.]

Since I don't have a band-saw, I like an elextric carving knife. If you're cutting 3" thick stuff, you'll stand a better chance of keeping it square if you measure & mark both sides. Also, as you're cutting, the foam will want to close back up & pinch the blades. If you pry open what you've already cut that will release the tension so it'll cut better.

For final shaping & rounding off corners I use a random orbital sander on low speed. I think I've got 180 grit paper on it. It makes nice, smooth corners & removes the knife marks on the flat sections.

[arhdc]

My List of preferred tools:

Band Saw
Small Japaneese Flush Cut Saw (they sell them in Harbor Freight and they are made in JAPAN)
80 Grit Flap Wheel on 4.5" grinder
40-80 Grit Sandpaper
Shurform
Belt Sader, both Table Top and Handheald


I tried Dragon Skin once and it was ok but broke up too much too fast for the price, good corse grit sandpaper was almost as good and way cheaper.

I like to carve what I can with the flap wheel on the grinder, I actually prefer that they be somewhat worn out as it makes it eaasyer to controll. You can get great curves the surface finish is nice and smooth. I also use the benchtop belt sander to make peices nice and smooth.

[Paddler]

for very fine and specific shaping I've made a custom tool.

What you'll need:
old pen (with the guts removed, bic or similar cheap pen) or very narrow bamboo, basically a tube to create a handle
coping saw blade

Create a "U" (the "U" can be as small as you like it, mine is about an inch wide) with the blade and insert the two ends of the coping saw into the end of your tube and fasten in place with what ever works. I made a vertical cut in the pen tube and made two shims and then used wire to clamp the opening around the blade ends.

Basically now you have the teeth that act as a nice rasp for those small areas and really fine tuning your shaping. It was also a really nice too for shaping foam boaters.