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Ragged Foamboard edges, IRON them!


Legendary member
Let me start off by saying this was NOT my idea, I do not know where I saw the idea first, but it has become my favorite new skill with foamboard planes.

The "problem" is I have a laser cutter... (I know, I know... sucks to be me) anyway, my pieces come out with a bit of the foam shrunken back from where the heat from the laser cut it.
Not only is this unsightly and probably affects the flight charastics a bit (at least it's one more thing I can blame my crashes on) but it's dangerous as well... I've gotten some nasty paper cuts (sometimes two in parallel!)

So, I gave using a covering iron to clean up the edges a try... and let me tell you, it has changed everything...

You can take an edge that looks like this;

And turn it into an edge that looks like this!

I suggest you give it a try if you haven't before and really want to dress up (and strengthen*) your builds.
*Yup, I've found that not only are the edges much more resilient to dings, but the process makes the parts MUCH stiffer as well (especially good on tail/control surfaces!)

Here's a quick video on the process;


Legendary member
Does this process work on non laser cut pieces? I scratch build 90% of my stuff with a good ole desktop printer and a xacto knife, so the foam isn't recessed back a bit from the edge from a laser.
It should work great, the extra bit of foam might give you even better results!

My favorite tool used to be my 3D printed bevel cutter, now the only time I really use it is on the leading edges of wings.


Elite member
Cup of proper tea is proven to increase the quality of your finished job 200%.
Practice on scrap foam first and watch the iron temp, you can make a big mess. I do all my parts on the bench, prior to assembly, just be sure which ones are the outside edges.


Well-known member
Do you use an iron sock or just bare iron? My wife showed interest in getting one of these sealing irons for her criket stuff and after seeing the advantages of it on foam board I'm probably gonna get one, share it with the wife. I don't have one yet as I've never owned a monocot plane. Is the hanger 9 iron on the FT store a decent iron?


Elite member
I just use the iron as is. I never iron clothes! Those craft irons are probably easier and good on tighter curves vs a clothes iron. I have found the melted foam was harder than glue, I smashed my SE5 into the ground inverted, ripped off a wing etc, the rolled edges stayed in shape. The foam melting bonds the paper really hard.