Dollar Tree foam board

rayg1022

Junior Member
Is there any videos, or how two's on using the dollar tree foam board? I printed out my tiled plans have them taped together and when I start the cut looks like crap. Any help? :(:confused:
 

Tritium

Amateur Extra Class K5TWM
Try a search for Experimental Airlines over at YouTube. You need a new blade for best cuts.

Thurmond
 

rockets4kids

Senior Member
The secret to cutting foam is a sharp blade. Unfortunately, both paper and foam will dull a blade in short order. If you plan to cut a lot of foam, do yourself a favor and order a 100-pack of x-acto blades.

A much better option, IMO, is to learn how to sharpen them. I treated x-acto blades as disposable for 30-odd years until I lost my supply box in a move. Not wanting to wait or pay the ridiculous prices for a 5-pack at the local store, I just sharpened the blade in my knife. Turns out it is remarkably easy to sharpen an x-acto blade, and touching up your blade several times during a build leads to a most enjoyable cutting experience.
 

Tritium

Amateur Extra Class K5TWM
Actually I do not like #11 x-acto blades. I much prefer Stanley Disposable Utility Knife Blades. They have 2 ends and are much tougher.

Thurmond
 

jhitesma

Some guy in the desert
Mentor
Yes, foam board dulls blades quick and dull blades create ragged nasty cuts.

xacto blades rock...but they seem to go dull really quick on foamboard for me. Utility blades aren't quite as sharp when new but they hold their edge a lot longer for me so I've switched to using utility blades for 90% of my foamboard work and only use an xacto when I need the extra precision.

The other two big tips I'd share are use a steel straight edge for straight cuts - not aluminum and not wood since both of those your blade can catch on! And keep the blade tilted so you use as much of the cutting edge as possible. Don't hold the blade so the cutting edge is perpendicular to the table, hold it at the steepest angle you can. That makes a HUGE difference in helping it cut since you're spreading the cut across more edge. It really helps a lot when cutting bevels, I use almost the whole cutting edge of a standard double sided utility blade cutting bevels and they go super smooth and easy for me now.
 

Jaxx

Posted a thousand or more times
The secret to cutting foam is a sharp blade. Unfortunately, both paper and foam will dull a blade in short order. If you plan to cut a lot of foam, do yourself a favor and order a 100-pack of x-acto blades.

A much better option, IMO, is to learn how to sharpen them. I treated x-acto blades as disposable for 30-odd years until I lost my supply box in a move. Not wanting to wait or pay the ridiculous prices for a 5-pack at the local store, I just sharpened the blade in my knife. Turns out it is remarkably easy to sharpen an x-acto blade, and touching up your blade several times during a build leads to a most enjoyable cutting experience.

How do you sharpen the blades?
 

rockets4kids

Senior Member
And keep the blade tilted so you use as much of the cutting edge as possible. Don't hold the blade so the cutting edge is perpendicular to the table, hold it at the steepest angle you can. That makes a HUGE difference in helping it cut since you're spreading the cut across more edge.

This is *not* the reason why cutting "on an angle" makes the cut easier. Cutting with the blade on an angle is slicing, where as holding the blade straight is push cutting. The edges on utility blades are finished with relatively coarse abrasives, leaving microscopic serrations on the edge. It is these serrations that actually do the cutting when you use a slice cut.

Push-cutting requires a *much* keener edge than slicing which is why you cannot get a good push cut even with a brand new blade. If you take a brand new blade and clean up the edge with a fine stone it will push cut much better.

These microscopic serrations also bare the brunt of the cutting force and are easily bent, fatigued, and ultimately broken off. This is why x-acto and utility blades get dull so quickly -- they were not *really* all that sharp to begin with.

I have found that the "Scary Sharp" technique works very well for x-acto blades. All you need is some 300 - 2000 grit wet-dry sandpaper and some plate glass. Soak a small piece of wet-dry sandpaper in water and stick it to the glass. This makes an excellent sharpening stone and costs little to nothing. I finish the edge using chrome-green polishing compound embedded in a piece of scrap leather. This works as both a strop to break the burr as well as final polishing. I have been told that any metal polishing compound will work here in a pinch, so again, you may already have all the items you need to make your own. Give the blade a few quick swipes (backwards) across the "sharpening strop" after every few minutes of heavy cutting to keep the edge in top shape at all times.

Sharpening an x-acto blade is *not* about being a cheap-skate. It is about keeping your tool at its sharpest at all times, and a sharp tool is a safe tool.
 

kingbee

Member
Hi rayg

can you tell us what your scratch build is or what plans you printed so we have a better idea on what your talking about ?
 

rcspaceflight

creator of virtual planes
It can take a while to get good at cutting foam board with an exatco knife. Going slow is key and sometimes it's better to lightly cut and go over your cut a second or third time. If you try to cut through all of the foam board at once, you can get too much drag from your cutting board and it'll turn out back.

A sharp blade is key. For straight lines you can use a metal ruler as a guide and go slow, and don't try to cut through the entire sheet all at once.
 

rockets4kids

Senior Member
It can take a while to get good at cutting foam board with an exatco knife. Going slow is key and sometimes it's better to lightly cut and go over your cut a second or third time. If you try to cut through all of the foam board at once, you can get too much drag from your cutting board and it'll turn out back.

There is absolutely no reason that an x-acto blade should have any trouble cutting through foam board in one pass at high speed. If your blade is not cutting like this it is dull and you should throw it away (or sharpen it!)

While blades rarely get dull as a result of the wearing away of material, the fine tip of an x-acto blade does indeed wear away quite rapidly when used against a cutting board. This is particularly bad if you do not have a proper cutting mat. When the tip of your blade is not sharp, it will indeed drag and not make a clean cut through the bottom sheet of paper even if it cuts the foam cleanly.

There is a *very* easy solution to this: re-point your blade. All you need to do is drag the *spine* of the blade across a coarse stone (or sandpaper) to develop a drop-point shape. Clean up the swarf/burr with a fine grit. with This has essentially the same effect as tearing off a section of a snap-off blade, although removing far less material. This will bring the tip back along the edge to portion that has not been worn away by constant contact with your cutting board. As such, no sharpening edge is required here.
 

rockets4kids

Senior Member
What do you use for sharpening, R4K?

Scroll back a few posts. I use 320, 600, and 1500 grit wet-dry sandpaper on float glass. This technique is known as the "scary sharp" method has been around since WW-II. It has become more common in recent years as sharpening stones have gotten very expensive and fine-grit sandpapers have become cheap and available. The serious knife geeks work up through 6000 - 8000 grit paper, but I have found that 1500 grit can give you a better edge than comes from the factory on an x-acto blade.

What you really want, though, is the sharpening strop. Mine is nothing more than a piece of craft leather loaded up with green buffing compound. You'll need to heat the leather up with a heat gun or hair dryer in order to melt the wax base. The "pros" use a heavy felt block and chrome oxide powder in an alcohol base and spray it onto the felt. This works like "slack belt sharpening" or "mousepad sharpening." The advantage here is that you don't need to worry about holding a consistent angle between the blade and the belt.

The secret is regular, quick, touch-ups while you are working. Once you have a good edge on the blade, just a few quick strokes on the strop after every few minutes of cutting is all you need. I will generally re-point the blade and give it a few strokes on the 1500 grit paper before or after each building session.

Even if you never learn how to hold a constant angle to sharpen the edge of a blade, you can *dramatically* prolong its useful life by nothing more than re-pointing and use of the sharpening-strop -- two things that *anyone* can learn is just a few minutes. And of course, there is nothing better to practice your edge sharpening technique on than a blade you were planning to dispose of anyway.
 

xuzme720

Dedicated foam bender
Mentor
Sorry, I thought you had a sharpening system in addition. I never got good free hand so have a few sharpeners I tried before I ended up with a Wicked Edge. I have some diamond stones I started with, then a Lansky based clone by Smith before I found the WE. I also have a few strops with various grade rouges for touchup and such. Never tried tossing a #11 on there but I don't see why it wouldn't work, but I have stropped a blade for shigs and gittles. Actually made a huge difference.
 

rockets4kids

Senior Member
If you are an edge geek and you have never worked on a #11 you should definitely give it a shot. You will quickly realize just how bad the factory edge really is.
 

xuzme720

Dedicated foam bender
Mentor
I know how bad they are...but I will still give it a shot. Might be some good practice going freehand on the diamond stones.
 

Craftydan

Hostage Taker of Quads
Staff member
Moderator
Mentor
Hi Rayg

take a look on this video this guys has and awsome tool to cut foam board.http://www.youtube.com/watch?v=nTUhhXQZWSI
maybe it could help you . also what are you building ?

I have one. Hobby Lobby was selling those for a while.

Doesn't work very well, and the blades are specialized -- now that Hobby Lobby isn't carrying them anymore, it'll be hard to hunt down replacements.

Used it a couple of times, then switched back to freehand x-acto blades . . . not that those are easy to use either . . .
 

augernaught

Augernaught
I have one. Hobby Lobby was selling those for a while.

Doesn't work very well, and the blades are specialized -- now that Hobby Lobby isn't carrying them anymore, it'll be hard to hunt down replacements.

Used it a couple of times, then switched back to freehand x-acto blades . . . not that those are easy to use either . . .


Dan, Xacto has a foam cutting tool also, and if I am not mistaken it uses the same blade as this tool.

http://xacto.com/products/cutting-solutions/knives/knives/Foamboard-Cutter.aspx

http://xacto.com/products/cutting-s...lades/Lightweight-Utility-Knife-Blade-8R.aspx

I got the one from Hobby Lobby when it was on clearance, and 2 packs of extra blades all for a
a price I couldn't pass up. While I agree it is not the best for all of our cutting needs,
I love the way you can set the blade depth to start the bevel cuts and channel cuts for the A/B folds.
That is pretty much all I use it for, but I was happy to find a source for blades.
It sure saves my nerves not having to pick little pieces of foam out of those channels!

I figure if someone mentions they can't find blades for their cutter, you could point them
in the right direction since you will probably see their post.