Replies to This Discussion

Permalink Reply by Zenith.Aero on April 19, 2012 at 10:55am

Good info!  Thanks for sharing.

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Permalink Reply by Dan Dempsey on April 20, 2012 at 5:20pm

I did the initial shaping on mine with a serated bread knife.  It worked to my satisfaction.

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Permalink Reply by Phill Barnes on April 20, 2012 at 6:36pm

Hi Jim

Just on a OH&S note,please remember that the gases produced from cutting foams with a hot wire are highly toxic. I did not see this mentioned in the article.

I used my bandsaw with a std coarse wood cutting blade with great results. This is the same blade that I use to cut all of my 6061-T6.

 

Regards

Phill

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Permalink Reply by Jim B Belcher on April 21, 2012 at 1:35pm

I did some research on Confor Foam producing toxic gas, but I haven't found any references on this. My understanding is that it is based on polyurethane, with additives. Lacking more detailed information, I can't really discuss this one pro or con. If you have a reference, it might be worth posting and incorporating.

I do have a statement of compliance with FAR 25.853(a) (1)(ii), which is says the material resists flamabilty. That's nice, but it doesn't really say what happens when someone intentionally heats it as I did.

My overall conclusion is that this fits in the same general category as a lot of aircraft chemicals and the like: if you don't know of a certainty that something is benign, a well ventilated area and protective clothing is a good idea.

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Permalink Reply by Louis W. Ott on April 21, 2012 at 1:07pm

An electric knife works perfectly. That is, as long as your wife doesn't find out. ;>)

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Permalink Reply by Jim B Belcher on April 21, 2012 at 1:42pm

There have been several comments about various cutting instruments working well with the foam. If it worked for you - great! I haven't had any luck with any cutting technique available to me doing much more than tearing the foam.That drove me to the hot wire cutter, a method I knew worked for me.

My advice to anyone trying any method of cutting the foam would be to try the tools you have that seem reasonable, rather than buy or build something else. If they don't work, try the methods outlined on this forum, and use the one that works best for you.

My wife can somehow find out when I have diverted things like electric knives to use as an aircraft tool. It may simply be that we've been married long enough that she knows my tricks.

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Permalink Reply by Jon Crew on April 21, 2012 at 5:40pm

OregonAero who charges big time for their confor foam seats, military headsets, etc.  has nothing but 8 grizzly 14 inch bandsaws to cut their foam.  Some people use turkey electric knives, which I have used as well as a good sharp knife and a band saw.  It is all in the operator.  no special tricks etc.  besides that, if you put the scrimback foam on the covering, and roughness will not be apparent.  There is a very good series of articles, May, June,2010 that are well worth the 20 bucks subscription to Kitplanes.  These articles will save you much time and give you a better result.  I know since I have spent many hours researching and bought books, these give you the most for your money. 

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