The corner of my Ventus landing gear door got bent and needs to be glued back to its former shape.
What epoxy should I use (I need a very small amount)
Need to clamp the piece while drying. What material to use so the clamp doesn't stay glued to the door....?
Dan

On Wednesday, March 11, 2015 at 11:23:27 AM UTC-4, wrote:
> The corner of my Ventus landing gear door got bent and needs to be glued back to its former shape.
> What epoxy should I use (I need a very small amount)
> Need to clamp the piece while drying. What material to use so the clamp doesn't stay glued to the door....?
> Dan

For this you could use a slow curing epoxy from your local hobby shop. I would not recommend 5 minute epoxy from your local hardware store.
Poly film placed over the repair before clamping will allow removal and can help make the shape better.
Good luck
UH

A Ventus door is glass right? I am trying to understand what "bent" means in this context. Is it that the resin is fractured leaving a corner of the door attached by some glass weave or does it mean a piece has broken off? For any large fix, you need to know what you are doing. Several on the forum can help in that case like JJ.

On Wed, 11 Mar 2015 08:52:51 -0700, unclhank wrote:

> On Wednesday, March 11, 2015 at 11:23:27 AM UTC-4,
> wrote:
>> The corner of my Ventus landing gear door got bent and needs to be
>> glued back to its former shape.
>> What epoxy should I use (I need a very small amount)
>> Need to clamp the piece while drying. What material to use so the clamp
>> doesn't stay glued to the door....?
>> Dan
>
> For this you could use a slow curing epoxy from your local hobby shop. I
> would not recommend 5 minute epoxy from your local hardware store.
> Poly film placed over the repair before clamping will allow removal and
> can help make the shape better.
> Good luck UH

The heat-shrink film used to wrap CDs, cigarettes, etc makes a good epoxy
release film. IIRC clingfilm also works, but do test it before using it
in anger.

Epoxy: 24hour epoxy gives a tougher result than the 5 minute epoxies,
which tend to be brittle when cured. However if your gear door shows
signs of delamination, one of the laminating epoxies would be better
because its relatively thin and so can be worked in to saturate the
delaminated/fractured area. The better hobby stores will stock it in
fairly small amounts: look for Z-poxy or SP113.

When I bought my Libelle, the front of its gear goods were decidedly moth-
eaten so I repaired the damaged front edges and corners:
- made a thin (1/32") ply laminated former that matched the outside curve
(a good quality cardboard lamination would also do since you'll only
use it once)
- covered that with release film (see above).
- cleaned up the more ragged door edges with knife, Dremel and sandpaper,
removing paint etc within 1/2" of the cleaned-up edges.
- taped and clamped the former onto the door
- used laminating epoxy/glasscloth/fibreglass mat to build up an
oversized section to replace the missing door area.
- let it harden thoroughly.
- took off the former and put a layer of 35gsm/1 oz/ft twill weave glass
cloth on the outside so it overlapped the bared area of the door and a
similar layer of thicker classcloth on the inside. This vastly
strengthens the join while leaving a nice surface to paint on the
outside
- then cut off the excess so the repaired doors were a nice fit in the
fuselage.
- painted the doors and refitted them.

I realise your repair is different, but working laminating epoxy into the
bent/damaged area, clamping it to a former to keep it straight while it
cures and then putting 100gsm/3 oz/ft glass cloth on the inside of the
door to cover the repaired crease should make a good job. This requires
laminating epoxy. Ordinary tubes of 24 hour epoxy are far too thick and
gooey for anything to do with glass-cloth: try using it with classcloth
and you'll just end up with a mega-sticky, epoxy-soaked ball of glasscloth
stuck to your hands.

A good hobby store (either online or highstreet) should have laminating
epoxy and glass cloth in fairly small quantities or, if you have a nearby
sailplane repair shop, they may let you have a small amount of epoxy and
some glasscloth offcuts. If all fails, try:

Aerospace Composite Products http://www.acp-composites.com/
or
Composite Structures Technology http://www.cstsales.com/

Both are in California and are extremely knowledgeable about
composite structures, materials and how to repair them.


--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |

Agree. ACP is good stuff. They sell everything he will need from mylar to peel-n-ply, glass and excellent laminating resin. This is all aircraft grade stuff in reasonable quantity. While MGS is the best, its only available by the gallon from Aircraft Spruce. going this route, fix it once and be done.
May want to post-cure too.

But with either hobby grade epoxy or CA+kicker(quick fix), likely not a lasting fix IMO.

I've always had good luck with wax paper as the release agent. You
probably already have some in the kitchen.

On 3/11/2015 4:25 PM, wrote:
> Agree. ACP is good stuff. They sell everything he will need from mylar to peel-n-ply, glass and excellent laminating resin. This is all aircraft grade stuff in reasonable quantity. While MGS is the best, its only available by the gallon from Aircraft Spruce. going this route, fix it once and be done.
> May want to post-cure too.
>
> But with either hobby grade epoxy or CA+kicker(quick fix), likely not a lasting fix IMO.

--
Dan Marotta

On Wednesday, March 11, 2015 at 8:51:33 PM UTC-4, Dan Marotta wrote:
> I've always had good luck with wax paper as the release agent.* You
> probably already have some in the kitchen.
>
> Perfect for making finishing harder. Use the plastic wrap next to the wax paper instead.
UH
>
>
>

On Wed, 11 Mar 2015 15:25:24 -0700, dbraun800 wrote:

>
> But with either hobby grade epoxy or CA+kicker(quick fix), likely not a
> lasting fix IMO.
>
Some hobby laminating epoxys may be junk but I've always had good results
with Z-poxy and SP113. I don't remember which one I used for my gear
doors but for sure it was one of those: probably the SP113 because the
repaired area is pale coloured. Z-poxy tends to be amber coloured while
SP113 is water-white.

That repair was done in winter 2006/7. The doors still looked great when
I checked them during the glider's annual inspection on the 2nd of this
month.


--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |

It is exactly like that: "the resin is fractured leaving a corner of the door attached by some glass weave" .
Dan
On Wednesday, March 11, 2015 at 3:04:14 PM UTC-4, wrote:
> A Ventus door is glass right? I am trying to understand what "bent" means in this context. Is it that the resin is fractured leaving a corner of the door attached by some glass weave or does it mean a piece has broken off? For any large fix, you need to know what you are doing. Several on the forum can help in that case like JJ.

On Thu, 12 Mar 2015 04:39:19 -0700, unclhank wrote:

> On Wednesday, March 11, 2015 at 8:51:33 PM UTC-4, Dan Marotta wrote:
>> I've always had good luck with wax paper as the release agent.Â* You
>> probably already have some in the kitchen.
>>
>> Perfect for making finishing harder. Use the plastic wrap next to the
>> wax paper instead.
> UH
>
Beeswax furniture polish is also good: its my favourite release agent if
I'm laying up small items on moulds made from car body filler. A couple
of coats, applied fairly liberally and rubbed down when works for me.

A single coat of the John Lewis Partnership beeswax polish (a thick
paste) applied to a scrap piece of bare, unvarnished, veneered shelving
and allowed to dry before I laid up a couple of layers of glasscloth
wetted out with SP113 directly on the polish was enough to cause an
immediate release after the epoxy had hardened. I stuck a knife blade
under one edge and the whole test patch, about 50mm x 50mm, popped right
off the wood.

As always, try any release agent on some scrap material before using it
for the real job. This advice probably applies in spades to furniture
polish: I always use the John Lewis Partnership beeswax polish but I can
well imagine that other brands may give different results.


--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |

On Thu, 12 Mar 2015 07:30:56 -0700, crosscountryboxco wrote:

> It is exactly like that: "the resin is fractured leaving a corner of the
> door attached by some glass weave" .
>
To me that's a two or three stage job for laminating resin plus a few
square inches of good quality glasscloth.

1) Wet out the fracture with the resin (you can thin it with methanol
if you must but be aware that will weaken the bond) and clamp it to
a former to hold it straight while it cures.
Don't forget the release film.

2) Sand off any lumps on the inside of the door and bond on a layer of
close weave cloth using laminating resin. 100 gsm/3 oz/ft cloth
should do the trick.

3) If the corner was just hanging by a thread, carefully sand off the
gelcoat etc on the outer surface and bond on a layer of light fine
weave cloth, 35 gsm/ 1-1.25 oz/ft weight. There is lighter cloth
but the thread count is low. You'll get a better finish with 35gsm
cloth. Then prepare and glasscloth surface and paint the outer
surface of the door.


--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |

Thanks for your advice.
I will get the laminating resin from ADC and follow all your advice.
Dan
On Thursday, March 12, 2015 at 4:22:41 PM UTC-4, Martin Gregorie wrote:
> On Thu, 12 Mar 2015 07:30:56 -0700, crosscountryboxco wrote:
>
> > It is exactly like that: "the resin is fractured leaving a corner of the
> > door attached by some glass weave" .
> >
> To me that's a two or three stage job for laminating resin plus a few
> square inches of good quality glasscloth.
>
> 1) Wet out the fracture with the resin (you can thin it with methanol
> if you must but be aware that will weaken the bond) and clamp it to
> a former to hold it straight while it cures.
> Don't forget the release film.
>
> 2) Sand off any lumps on the inside of the door and bond on a layer of
> close weave cloth using laminating resin. 100 gsm/3 oz/ft cloth
> should do the trick.
>
> 3) If the corner was just hanging by a thread, carefully sand off the
> gelcoat etc on the outer surface and bond on a layer of light fine
> weave cloth, 35 gsm/ 1-1.25 oz/ft weight. There is lighter cloth
> but the thread count is low. You'll get a better finish with 35gsm
> cloth. Then prepare and glasscloth surface and paint the outer
> surface of the door.
>
>
> --
> martin@ | Martin Gregorie
> gregorie. | Essex, UK
> org |

On Fri, 13 Mar 2015 06:40:04 -0700, crosscountryboxco wrote:

Oops -that should read:
>> 3) If the corner was just hanging by a thread, carefully sand off the
>> gelcoat etc on the outer surface and bond on a layer of light fine
>> weave cloth, 35 gsm/ 1-1.25 oz/ft weight. There is lighter cloth but
>> the thread count is low. You'll get a better finish with 35gsm
>> cloth. Then prepare and glasscloth surface and paint the outer
>> surface of the door.

Then prepare new glasscloth surface. Use fine sandpaper (180-200 grit on
a sanding block) to get a smooth surface on the glasscloth and feather
its edges before painting it.

The nice thing about good quality 35gsm cloth is that the epoxy usually
fills the weave pretty well. This means you don't need to sand it much to
get rid of the fabric effect after the epoxy has cured.


--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |