Hi Mounties, I need to make several foam storage mounts for small ceramics. I'm interested in hearing about your favorite knives to use for carving small rounded shapes in ethafoam. Any advice appreciated! Thanks, Gina
Ceramic knives are excellent for shaping ethafoam. I purchased a set of Mighty Fine Online high quality and very economical ceramic knives from Amazon. See attached image of some of the knives and sheaths from set.
Good luck with your project!
Adella J. Valdez
Museum Curator II
California State Parks
Field, George RBCM:EX
We also use an electric hot knife, we buy the blade material in a roll and we shape the blade to match what we want. Works well with practice.
joanne harris 6/16/18
Hi Gina, I like ceramic knives, they are really sharp and easily handled because they are lightweight.
You can also try sharpening the end of a thin-walled metal tube the diameter that you need on a disc or belt sander- this an easy way to cut nice holes and plugs in ethafoam. You can also easily shape ethafoam with a disc sander- a little messy, but works well.
Hope this helps!
Keith Jentzsch 6/17/18
http://goodsjapan.com/takagi-japanese-plasterboard-drywall-gysum-jab-saw-16cm-steel-blade-1730-p.asp I'm a wood and metal based worker among other tech operations but according to hand based cutting saw options; Japanese hand saws are really the best cutting design. Outside Japanese, there are other well designed hand saw cutters. Good Luck!🐙 KJ, Keith Jentzsch Chief Preparator & Operations Manager Gregory Allicar Museum of Art
Hi Gina, It sounds like you are wanting to carve bowl shaped cavities which is certainly something that is done. The hot knife solution already mentioned is one approach. Another I have seen, but not had much success with personally, is taking a hacksaw blade, grinding off the teeth to a knife edge and bending it over a wooden handle to make a "scoop shaped" knife. The other common option for storing pots though is an additive approach rather than a subtractive one (wedges vs carving). In terms of handling - especially with fragile vessels - it is advisable to be able to support the object from underneath while lifting. In a cavity you would need to remove lifting slots anyway. It is usually easier to make curved wedges rather than a curved cavity. I did a rehousing project for 10,000 ceramic vessels a while back that utilized mass-produced wedges that went really well. You obviously don't need mass production but the technique is still good. It was used in an article that was actually about making posters but you could see if it is helpful in any way. Here is the link-
Larry Hutchings 6/18/18
I buy the cheapest possible kitchen knives at the local hardware store. The rough edges of the poorly-sharpened blades act like micro-serrations; I find they cut foam easily and quickly using a sawing motion. With narrow-bladed knives, the low quality metal is also easily bent to curved shapes for hollowing cavities.
Jamie Hascall 6/18/18
Re: [mountmaking-forum] Re: Foam carving knives That's a great tip. I’ll have to look for a good set to have around. I tend to take a little different tack and use OLFA retractable-blade knives for cutting foam. The ability to quickly change to a new sharp blade is a real help. The snap-blades can be a little bit of a problem when doing heavy carving, but they make non-snap style blades as well which are some of my favorites. Jamie
Paul Brower 6/18/18
I have several of these "hacksaw blade" knives and I bend them to the shape I'm aiming for. It's a trick I saw in a custom motorcycle shop years ago. Motorcycle seats use different foam that we do but it cuts the same. Paul Browe
G bee 6/20/18
So many great ideas, thank you! My experience using Benchmark's foam cutting knives was worse than using a dull butterknife. I use a sharp upholstery cutter for larger general shapes, but this conversation gives me a lot of options for more delicate, concave shapes.Thanks, Gina
When I worked for US Art I found that fish filleting knives work exceptionally well! They are thin, tapered, and flexible (to a degree) so they work well for a variety of situations and shapes. You can also come with a sheath that has a sharpening stone built into it so the knife stays constantly sharp. Hope this help!B.j.
B.j. Vogt Exhibit Preparator/Mountmaker
Missouri History Museum
Lindell and DeBaliviere in Forest Park
Tel: 314.361-7363| Fax: 314.361-6828
Suzi McG 6/26/18
Re: [mountmaking-forum] Re: Foam carving knives So far my favorite is a cheap kitchen knife I picked up in my grocery store. I've also used an avocado slicer and pineapple corer that I modified. Reading this affirms my suspicion that we spend a lot more time trying to come up with tools to get the job done right than it sometimes takes to do the job. Best, Suzi