Building EPP LEG model in ZA

Drusky · May 30, 2007, 02:26 AM

Howzit mah chinahs.

EPP = Expanded Polypropylene
EPS = Expanded Polystyrene

I'm sure lots of you have wanted to try some of the ideas you see on the American threads only to come up against the wall of "we don't have that stuff here."

I had this issue with the building of my Leading Edge Gliders EPP slope soarer. Aragon and Minifly kindly put me on to ZA alternatives and place of purchase.

It's called Goop, or Marine Goop. Used to glue models together and thinned it out with Xylenol or Toluene it is paint it on wing leading edges and fuselage belly for added impact resistance.
Our equivalent is Sole Saver available from Sportsmans Warehouse and manufactured by Hitec, it smells like bostic and stick like hell. Sadly ours is an off yellow colour, they get it clear in the US.

It's called PU or polyurethane glue. It is used to fill the remaining gap in spar slots and finish (bed) EPP wings. I have used it to secure lead in the nose of my Bard sloper. The stuff looks like honey but slowly foams when exposed to an atmosphere containing moisture. Generally you wet your glueing surface before applying the PU, it will however foam without this help I think the moisture improves the bond though.
I've found it only recently at Servistar, it contains no solvent and thus does not attack EPS. Makes same type of foam that you get in those propellant cans. This is just far more handy in the liquid form.

Please post alternate materials you have discovered here and place of purchase.

Thanks,
Andrew

aragon · May 30, 2007, 06:01 PM

For lightweight spackle, check out alcolin's litefill. Don't get from the hobby shop as it costs twice as much and is just litefill rebranded in a generic plastic tub...

ziggx · May 31, 2007, 03:23 AM

Hi Andrew

I was working with some goop last night and it is similar in uses to sloe saver but the goop has a much more silicone feel to it. The other thing that I am looking for is a packing tape with a much fine fibre than the local avialable one so you dont get the lines after covering it.

I think that the next time that someone orders a kit from leading edge we should put a order in for goop and tape. Just fill the box up. We can just split the freight up afterwards.

Cheers

Dion

ziggx · May 31, 2007, 05:14 AM

This is another interesting finishing for epp.

Ca and fibre glass cloth. http://www.futureslopedesigns.com/ma...20Page%202.pdf

I have not tried this method yet but it does sound interesting I will try and do it on some wing beds to see how they come out and will report back.
When I built my Jw they recommended thick ca for putting in the spars
it used queit a bit of ca but also made the epp queit stiff. So it should be interesting.

Cheers

Dion

Drusky · Jun 12, 2007, 05:39 AM

I took an old bare EPP wing bed and smeared it with some PU glue (alcolin stuff) on the flat side. I had a piece of glass waxed with Mr Min ready. I put the wing bed flat side down on the glass and weighted it down with magazines.

The end result is a nice smooth finish which adheres well to the EPP but little structural improvement.

Drusky · Jun 15, 2007, 02:15 AM

Can't seem to find this "roofing tape". Dion (ziggyx) suggested the tape they use for dry walling but he says it only comes in 50mm wide strips. Anyone have any ideas?

Drusky · Aug 20, 2007, 04:08 AM

Update:
I got hold of RHINO TAPE used for dry walling. There is definitely a lot of potential for this type of build method.

Spray EPP wing with 3M90.
Apply rhino tape.
Apply a thin layer of PU glue to waxed mylars.
Put to sleep in wing beds and weigh down with magazines, make sure your mylars are dead straight no wrinkles. Work surface must also be level
Cut off excess foam, spackle rough edges, sand and paint.

aragon · Sep 06, 2007, 05:59 PM

Drusky, where do you get Mylar in ZA if I may ask?

Declined · Sep 13, 2007, 02:44 PM

Quote:

It's called Goop, or Marine Goop. Used to glue models together and thinned it out with Xylenol or Toluene it is paint it on wing leading edges and fuselage belly for added impact resistance.
Our equivalent is Sole Saver available from Sportsmans Warehouse and manufactured by Hitec, it smells like bostic and stick like hell. Sadly ours is an off yellow colour, they get it clear in the US.

couldnt u just use epoxy instead?

it sets pretty clear,doesnt take much in the way of quantity and is damn strong!

aragon · Sep 14, 2007, 06:06 AM

Epoxy sets hard and is brittle. Goop remains flexible while still having huge amounts of tensile and sheer strength. Its flexibility gives it more strength in applications like this, because it is able to absorb impacts without damaging the bond.

Declined · Sep 14, 2007, 09:13 AM

oh ok

just use epoxy and dont crash instead =)

Drusky · Oct 03, 2007, 01:44 AM

Sorry aragon, bit of a delayed reply. In PE I would ask Specialist Composites to get it for me. You may have to import some kevlar but I would try a local yacht builder or the CT version of Specialist Composites (there must be one) first.

spacey · Oct 03, 2007, 02:57 AM

Nobody mentioned so I'm just checking. Is Xylenol or Toluene available here and from where if so? I have to start working on my Windrider Bat soon but all this special stuff required things are really slowing me down, the project is kind of a mountain in front of me now.

Thanks,
Rudolf

aragon · Oct 05, 2007, 03:46 AM

Spacey, I got Toluene from Fawkes Bros here in Cape Town.

cvanscho · Oct 19, 2007, 05:30 AM

Hello you guys down there!

For PU glue, the best of the best is "Balcotan" by Brummer (yelow plastic bottles). It's used by all the pro custom joinery guys. I was lucky to have stocked up a whole pile of bottles before I moved to Ireland.

I have been experimenting with Balcotan and that open-weave jointing tape, as we also cannot get "roofing tape" over here. See my thread here:http://www.rcmf.co.uk/4um/index.php/topic,43882.0.html.

Goop is also hard to get here, I recently bought some from the US on fleaBay, see:http://www.rcmf.co.uk/4um/index.php/topic,44065.0.html.

After making enquiries with the US manufacturer, a distributer in the UK has been found (although they are not really marketing it properly, but it is available). Maybe the same applies in SA? Google "amazing goop".

The important thing to keep in mind with finishing EPP, is that the only reason we use it, is it "gives" on hitting something, and tends to "sproing" back to shape. It's not a particularly good foam for getting a decent shape or finish. Any finishing should not destroy those forgiving and flexible properties, and must be able to give as well as the EPP. Otherwise we might as well use hard foam and epoxy/glass, (or balsa) and be done with it.

Oh, yes, one last tip - use latex gloves when working with PU - it cannot be removed from skin, and goes a lovely black colour!

Cheers from Ireland

Chris (aka Woodstock)(because I fly like him)

May 30, 2007, 02:26 AM	#1
Drusky loamy foamie Join Date: Jun 2006 Location: Port Elizabeth, South Africa Posts: 569	Building EPP LEG model in ZA Howzit mah chinahs. EPP = Expanded Polypropylene EPS = Expanded Polystyrene I'm sure lots of you have wanted to try some of the ideas you see on the American threads only to come up against the wall of "we don't have that stuff here." I had this issue with the building of my Leading Edge Gliders EPP slope soarer. Aragon and Minifly kindly put me on to ZA alternatives and place of purchase. It's called Goop, or Marine Goop. Used to glue models together and thinned it out with Xylenol or Toluene it is paint it on wing leading edges and fuselage belly for added impact resistance. Our equivalent is Sole Saver available from Sportsmans Warehouse and manufactured by Hitec, it smells like bostic and stick like hell. Sadly ours is an off yellow colour, they get it clear in the US. It's called PU or polyurethane glue. It is used to fill the remaining gap in spar slots and finish (bed) EPP wings. I have used it to secure lead in the nose of my Bard sloper. The stuff looks like honey but slowly foams when exposed to an atmosphere containing moisture. Generally you wet your glueing surface before applying the PU, it will however foam without this help I think the moisture improves the bond though. I've found it only recently at Servistar, it contains no solvent and thus does not attack EPS. Makes same type of foam that you get in those propellant cans. This is just far more handy in the liquid form. Please post alternate materials you have discovered here and place of purchase. Thanks, Andrew Last edited by Drusky; Jun 12, 2007 at 05:30 AM.

May 31, 2007, 03:23 AM	#3
ziggx Registered User Join Date: Feb 2007 Posts: 304	epp supplies Hi Andrew I was working with some goop last night and it is similar in uses to sloe saver but the goop has a much more silicone feel to it. The other thing that I am looking for is a packing tape with a much fine fibre than the local avialable one so you dont get the lines after covering it. I think that the next time that someone orders a kit from leading edge we should put a order in for goop and tape. Just fill the box up. We can just split the freight up afterwards. Cheers Dion Last edited by ziggx; May 31, 2007 at 05:21 AM.

May 31, 2007, 05:14 AM	#4
ziggx Registered User Join Date: Feb 2007 Posts: 304	Different finishing This is another interesting finishing for epp. Ca and fibre glass cloth. http://www.futureslopedesigns.com/ma...20Page%202.pdf I have not tried this method yet but it does sound interesting I will try and do it on some wing beds to see how they come out and will report back. When I built my Jw they recommended thick ca for putting in the spars it used queit a bit of ca but also made the epp queit stiff. So it should be interesting. Cheers Dion

Aug 20, 2007, 04:08 AM	#7
Drusky loamy foamie Join Date: Jun 2006 Location: Port Elizabeth, South Africa Posts: 569	Update: I got hold of RHINO TAPE used for dry walling. There is definitely a lot of potential for this type of build method. Spray EPP wing with 3M90. Apply rhino tape. Apply a thin layer of PU glue to waxed mylars. Put to sleep in wing beds and weigh down with magazines, make sure your mylars are dead straight no wrinkles. Work surface must also be level Cut off excess foam, spackle rough edges, sand and paint.

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May 30, 2007, 06:01 PM	#2
aragon Registered User Join Date: Jan 2005 Location: Cape Town, South Africa Posts: 5,131	For lightweight spackle, check out alcolin's litefill. Don't get from the hobby shop as it costs twice as much and is just litefill rebranded in a generic plastic tub...

Jun 12, 2007, 05:39 AM	#5
Drusky loamy foamie Join Date: Jun 2006 Location: Port Elizabeth, South Africa Posts: 569	I took an old bare EPP wing bed and smeared it with some PU glue (alcolin stuff) on the flat side. I had a piece of glass waxed with Mr Min ready. I put the wing bed flat side down on the glass and weighted it down with magazines. The end result is a nice smooth finish which adheres well to the EPP but little structural improvement.

Jun 15, 2007, 02:15 AM	#6
Drusky loamy foamie Join Date: Jun 2006 Location: Port Elizabeth, South Africa Posts: 569	Can't seem to find this "roofing tape". Dion (ziggyx) suggested the tape they use for dry walling but he says it only comes in 50mm wide strips. Anyone have any ideas?

Sep 06, 2007, 05:59 PM	#8
aragon Registered User Join Date: Jan 2005 Location: Cape Town, South Africa Posts: 5,131	Drusky, where do you get Mylar in ZA if I may ask?

Sep 14, 2007, 06:06 AM	#10
aragon Registered User Join Date: Jan 2005 Location: Cape Town, South Africa Posts: 5,131	Epoxy sets hard and is brittle. Goop remains flexible while still having huge amounts of tensile and sheer strength. Its flexibility gives it more strength in applications like this, because it is able to absorb impacts without damaging the bond.

Sep 14, 2007, 09:13 AM	#11
Declined Teh Crash MAster! Join Date: Jul 2007 Location: south africa Posts: 76	oh ok just use epoxy and dont crash instead =)

Oct 03, 2007, 01:44 AM	#12
Drusky loamy foamie Join Date: Jun 2006 Location: Port Elizabeth, South Africa Posts: 569	Sorry aragon, bit of a delayed reply. In PE I would ask Specialist Composites to get it for me. You may have to import some kevlar but I would try a local yacht builder or the CT version of Specialist Composites (there must be one) first.

Oct 03, 2007, 02:57 AM	#13
spacey Registered User Join Date: Mar 2004 Location: Pretoria, South Africa Posts: 511	Nobody mentioned so I'm just checking. Is Xylenol or Toluene available here and from where if so? I have to start working on my Windrider Bat soon but all this special stuff required things are really slowing me down, the project is kind of a mountain in front of me now. Thanks, Rudolf

Oct 05, 2007, 03:46 AM	#14
aragon Registered User Join Date: Jan 2005 Location: Cape Town, South Africa Posts: 5,131	Spacey, I got Toluene from Fawkes Bros here in Cape Town.

Oct 19, 2007, 05:30 AM	#15
cvanscho Chris (aka Woodstock) Join Date: Dec 2005 Location: Tralee, Co. Kerry, Ireland Posts: 1,806	Hello you guys down there! For PU glue, the best of the best is "Balcotan" by Brummer (yelow plastic bottles). It's used by all the pro custom joinery guys. I was lucky to have stocked up a whole pile of bottles before I moved to Ireland. I have been experimenting with Balcotan and that open-weave jointing tape, as we also cannot get "roofing tape" over here. See my thread here:http://www.rcmf.co.uk/4um/index.php/topic,43882.0.html. Goop is also hard to get here, I recently bought some from the US on fleaBay, see:http://www.rcmf.co.uk/4um/index.php/topic,44065.0.html. After making enquiries with the US manufacturer, a distributer in the UK has been found (although they are not really marketing it properly, but it is available). Maybe the same applies in SA? Google "amazing goop". The important thing to keep in mind with finishing EPP, is that the only reason we use it, is it "gives" on hitting something, and tends to "sproing" back to shape. It's not a particularly good foam for getting a decent shape or finish. Any finishing should not destroy those forgiving and flexible properties, and must be able to give as well as the EPP. Otherwise we might as well use hard foam and epoxy/glass, (or balsa) and be done with it. Oh, yes, one last tip - use latex gloves when working with PU - it cannot be removed from skin, and goes a lovely black colour! Cheers from Ireland Chris (aka Woodstock)(because I fly like him)