Today's Message Index:
----------------------
1. 01:16 AM - Re: W20 Bracket spec (John Wighton)
2. 01:56 AM - Re: W20 Bracket spec (D McFadyean)
3. 08:22 AM - Re: W20 Bracket spec (JonathanMilbank)
4. 10:10 AM - How much to sand for filler (n7188u)
5. 10:25 AM - Re: How much to sand for filler (n7188u)
6. 12:55 PM - Re: How much to sand for filler (timward)
7. 06:38 PM - Re: W20 Bracket spec (William Daniell)
Message 1
| INDEX | Back to Main INDEX |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: W20 Bracket spec |
Use a minimum of 6061 T6, probably 2024 T3 will be readily available and gives
slightly higher UTS.
--------
John Wighton
Europa XS trigear G-IPOD
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=498636#498636
Message 2
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: W20 Bracket spec |
H30, I believe. But why not ask the Factory what they use now?
Duncan McF.
> On 02 October 2020 at 00:30 Brian Phillips <barp99@gmail.com mailto:barp99@gmail.com > wrote:
>
>
> I am currently attaching the port flap to the wing on my trigear, I
> find, for whatever reason, that the W20 bracket is too short by 12mm
> when the flap is in its correct position. Rather than live with this
> mismatch at the bolted joint, I will make up a new longer W20 bracket.
> Does anyone know what grade and temper these aluminium brackets are made
> from?
>
> Brian
> Sydney, Aus.
>
Message 3
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: W20 Bracket spec |
It's now 25 years since I built my Classic wings with the foam cores and I honestly
can't remember the finer details, but are all the W20 brackets on each wing
the same size, or are they made progressively smaller from inboard to outboard?
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=498638#498638
Message 4
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | How much to sand for filler |
Dear forum members,
I always had a question, never having a chance to see in person a properly done
sample of how much you should sand a control surface layup before applying filler
to the control surfaces.
If you lightly scuff the surface with 80 grit all you get is minute dullness at
the crest of the layup fiber bundles. I would say not even 10-20% scuffed. If
you go more then you are indeed cutting through the fibers. but my understanding
is that anything that is still glossy provides basically zero bonding strength.
So what is that magical point at which you stop sanding and it is sufficient bonding
for the filer.
BTW, one time I spoke with a gentleman that happened to run the R&D department
at Lancair during the certification of the Columbia 300. He told me they did extensive
testing on how much to sand before a structural bond. He indicated that
the highest structural strength with bonded components would be achieved by
doing very detailed cleaning and then just using scuff pads to lightly scuff
the surface. The resulting bonded structure was stronger than cleaning and sanding
with coarse sandpaper until all surfaces are dull. Now, he explained we are
not talking about the bond strength. He explained that what they tested is
for the overall strength of the bonded structure and his explanation is that using
coarse sandpaper damages the substrate layups and overall you end up with
a weaker structure. Then he added they still ended up scuffing until dull in
production because the FAA would not accept that just using scuff pads and ending
with a surface that still looks glossy would be OK despite all the testing.
I found the story interesting.
Best regards,
Chris
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=498640#498640
Message 5
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: How much to sand for filler |
BTW, Rutan wrote in his booklet "Moldless Composite Homebuilt Sandwich Aircraft
Construction" that if you wait until the epoxy fully cures "you will have to
sand the fiberglass surface to a dull finish"
Hence a lifetime of confusion for me.
when we discuss this can we estimate how much dullness you want in terms of % of
dull surface?
Best,
Chris
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=498641#498641
Message 6
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: How much to sand for filler |
Hi Chris,
My Air New Zealand painter who painted my aircraft Boeing White, said to go down
to 180 grit only. Finer will cause a lack of bonding for the paint.
Tim
Sent from my iPad
Tim Ward
12 Waiwetu Street, Fendalton, CHRISTCHURCH. NZ 8052
ward.t@xtra.co.nz
021 0640221
> On 4/10/2020, at 6:21 AM, n7188u <chmgarb@gmail.com> wrote:
>
>
> Dear forum members,
>
> I always had a question, never having a chance to see in person a properly done
sample of how much you should sand a control surface layup before applying
filler to the control surfaces.
>
> If you lightly scuff the surface with 80 grit all you get is minute dullness
at the crest of the layup fiber bundles. I would say not even 10-20% scuffed.
If you go more then you are indeed cutting through the fibers. but my understanding
is that anything that is still glossy provides basically zero bonding strength.
>
> So what is that magical point at which you stop sanding and it is sufficient
bonding for the filer.
>
> BTW, one time I spoke with a gentleman that happened to run the R&D department
at Lancair during the certification of the Columbia 300. He told me they did
extensive testing on how much to sand before a structural bond. He indicated
that the highest structural strength with bonded components would be achieved
by doing very detailed cleaning and then just using scuff pads to lightly scuff
the surface. The resulting bonded structure was stronger than cleaning and sanding
with coarse sandpaper until all surfaces are dull. Now, he explained we
are not talking about the bond strength. He explained that what they tested is
for the overall strength of the bonded structure and his explanation is that
using coarse sandpaper damages the substrate layups and overall you end up with
a weaker structure. Then he added they still ended up scuffing until dull in
production because the FAA would not accept that just using scuff pads and ending
with a surface that still looks glossy would be !
> OK despite all the testing.
>
> I found the story interesting.
>
> Best regards,
> Chris
>
>
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=498640#498640
>
>
>
>
>
>
>
>
>
Message 7
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: W20 Bracket spec |
Brian
It looks to me as thought the lower surface of the flap is not aligned with
the lower surface of the wing...or is it just how it looks in the photo?
Will
William Daniell
LONGPORT
+57 310 295 0744
On Thu, Oct 1, 2020, 19:49 Brian Phillips <barp99@gmail.com> wrote:
>
> I am currently attaching the port flap to the wing on my trigear, I
> find, for whatever reason, that the W20 bracket is too short by 12mm
> when the flap is in its correct position. Rather than live with this
> mismatch at the bolted joint, I will make up a new longer W20 bracket.
> Does anyone know what grade and temper these aluminium brackets are made
> from?
>
> Brian
> Sydney, Aus.
>
>
Other Matronics Email List Services
These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.
-- Please support this service by making your Contribution today! --
|