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Foam used to close up fairings on EMP

Surfdoc

Member
Getting ready to work on the fiberglass for the empennage. Does anyone have a good source for the foam? So little is needed. Just wondering where any other builders purchased their foam.
 
If there is a craft store in your town (Michaels, Big Lots, sometimes Wal-Mart) you can use the green flower arranging foam. Or balsa. Or the pink insulation board from the local home center.
 
Home Depot

My local Home Depot sells the pink (dense) foam in 2' X 2' squares - more than enough for the empennage, flaps, and ailerons.
They only had ?" foam so there was a bit of cutting to get the foam down below flush (to apply fiberglass). I've not seen any ?" foam, but if you can find it it would be a lot less work.

Use an epoxy/flox slurry; very little to hold the foam in place.

If you've not assembled the items on the plane, simply press the foam up against the component sufficiently to cause the outline to be impressed into the foam, cut and sand to fit.
 
Getting ready to work on the fiberglass for the empennage. Does anyone have a good source for the foam? So little is needed. Just wondering where any other builders purchased their foam.

No particular reason to use foam. For example, aircraft plywood is good core material, or just do a little two ply layup in a flat surface, then cut out whatever core shape you need after cure.

Tack the core into place with a few dabs of 5 minute epoxy, then come back and do the cover layups.
 
I may be able to print a pattern with a nice concave or flat surface. Cover with fiberglass.

I made mine several years ago using balsa and sanded in a concave surface. I like them but they were a pain to make. It could be done easier with a printed pattern.

vert stab, slightly concave allows constant clearance thru the motion, less chance for ice binding
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horizontal stab, slightly concave allows constant clearance thru the motion, less chance for ice binding
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I also added some glass to backside of the balsa to be sure it would not become loose. That was probably not needed but it's in there.
 
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I just made some out of scrap aluminium sheet.

BUT - in another of my less-than-stellar moments - didn't account for the fact they spread when not installed in their respective ribs, so when I did try to install the tip fairings in their stabilisers, they were too wide. :mad:

So now most have a crease in them where I bend the aluminium sheet to make them fit until I re-did them 'later'. Later still hasn't arrived....
 
Fixate the control surface in perfect alignment with the stabilizer. Lot of ways to do it. A long #6 in the gap between the counterweight arm and the end of the stabilizer works well.

Cleco the end caps to the stabilizer and control surface. Eyeball them for alignment, which is important, because they tend to be misshapen. Cut whatever bulkhead material you're using so when inserted, it forces the shape into alignment. Tack them into place with a few dabs of 5 min epoxy, which locks all the dimensions when removed for filling/shaping/finishing.
 
curved finished.

3/16 gap at the outer edges, 3/16+ clearance on the inside to hopefully prevent ice wedge jamming on the inside. my thinking was the outer edge would act as a knife. hopefully, I never need it, but I have had small amount of ice.

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