Glassing Fins
Kev Timmins
what's the best type of Glass Cloth & resin for Glassing fins.
Best place to buy online ?
Any comments appreciated.
Kev T
Niall Oswald
news:d6fb4h$20s$1...@newsg2.svr.pol.co.uk...
West Systems epoxy is popular - its available in many places that sell
boat-building stuff.
I bought mine from from CFS fibreglass supplies http://www.cfsnet.co.uk/ but
I suspect there are cheaper places.
If you're not planning on doing loads of composite stuff, I would suggest
getting the 'junior pack' and some plastic syringes of various sizes for
measuring out the mixes. It mixes 5:1 resin:hardner by mass or volume.
For bonding with it you really need some kind of 'filler', but for 'glassing
just use it 'straight'.
I've got the '206' slow hardner, it really does take a long time (good 12-24
hours before it stops being sticky).
As for glass cloth, I also got mine from CFS, but they don't have the same
range any more. Just make sure you don't get chopped strand mat!
--
Niall Oswald
================================
http://www.bits.bris.ac.uk/niall
UKRA 1345
EARS 1151
MARS
Init 6
for small amounts. Fast delivery and pretty good prices.
--
Colin MacLaren
UKRA #1283 RSO L2
TRA #10249 L2
Mel
I know people seem to go for special resins and glass supplies; but, do
you have a Halfords anywhere near you?
For the size of fin or whatever and performance requirements and ease
of getting hold of the stuff, your local Halfords car repair kit is
fine.
Glass tissue gives a good surface finish, but so will a piece of old
stocking nylon (sorry, I mean tights nylon) or an length of old shirt
material.
Use the glass mat if you think it's necessary.
Get hold of two pieces of thick glass, if you are not supersticious,
two mirror tiles are good (you may crack one at the release stage).
Silicon polish the mirrors, leave it on.
Resin the mirrors.
Dab in the surface material.
Paint the fin material, Ply*, Balsa*, MDF* whatever, with resin.
Sandwich the fin material between the finish surfaces on the mirrors
and add weights to the sandwich.
Once cured, lever the glass off and marvel at the superb, CHEAP finish
on the glassed fins.
Remember, Hammerite gives a great easy one coat finish to your whole
rocket.
Any "performance differentials" due to surface texture are going to be
less than the differences between the performances of any two motors of
the same thrust rating at this level of rocketry
Regards
Mel S
UKRA 1045
L2 RSO
Mel
Niall Oswald
news:1116438876.8...@g49g2000cwa.googlegroups.com...
> I know people seem to go for special resins and glass supplies; but, do
> you have a Halfords anywhere near you?
> For the size of fin or whatever and performance requirements and ease
> of getting hold of the stuff, your local Halfords car repair kit is
> fine.
> Glass tissue gives a good surface finish, but so will a piece of old
> stocking nylon (sorry, I mean tights nylon) or an length of old shirt
> material.
Do the halfords kits come with woven glass cloth? I looked at one but it had
CSM and polyester resin in it :(
> Use the glass mat if you think it's necessary.
> Get hold of two pieces of thick glass, if you are not supersticious,
> two mirror tiles are good (you may crack one at the release stage).
> Silicon polish the mirrors, leave it on.
> Resin the mirrors.
> Dab in the surface material.
> Paint the fin material, Ply*, Balsa*, MDF* whatever, with resin.
> Sandwich the fin material between the finish surfaces on the mirrors
> and add weights to the sandwich.
> Once cured, lever the glass off and marvel at the superb, CHEAP finish
> on the glassed fins.
How much strength does 'glassing' with fabric add? While it gives a good
finish I think that if you're looking for strength going with glass cloth is
the best way - its about £3 per square metre and 1 square metre will cover a
lot of rocket. I'm guessing Kev is looking for strength after his broken
fin.
> Remember, Hammerite gives a great easy one coat finish to your whole
> rocket.
> Any "performance differentials" due to surface texture are going to be
> less than the differences between the performances of any two motors of
> the same thrust rating at this level of rocketry
That depends how fast you're flying and how much you care about altitude
(ask Damian!). I know its only a sim, but switching the finish properties
for a rocket I'm working on from all 'polished' to all 'unfinished' makes a
difference of 3000ft (from 8800ft to 5800ft). The sim also indicates a matt
finish costing over 1000ft compared to a polished finish. Perhaps not
relevant here, but something to bear in mind.
Of course in normal circumstances, motor variation, weather conditions etc
will more than likely make far more of a difference.
Damian Burrin
> had CSM and polyester resin in it :(
The Halford kits (Dave's i think they're called)with the glass cloth are
fine for just glassing fins, i personally used the halford kits (the Daves
ones again) that has the mat rather than cloth and layered two or three
strips over the fin fillet.
I would be very wary of the polyester resin and use epoxy resin instead.
I've not tried using the halfords glass for doing complete bt's though i
prefer to use the international stuff that Pete and my local boat yard sell.
I do know Chris E has a very cheap per m supplier but the carriage was high
so only cheap if your ordering 3 or 4 meters worth or could collect.
Damian
--
Damian Burrin
UKRA 1159 Level 2 RSO
EARS 1115
http://www.ukrocketry.com
http://www.larf-rocketry.co.uk
"Niall Oswald" <no4...@schtop.bris.com.ac.com.uk> wrote in message
news:IGp9K...@bath.ac.uk...
Niall Oswald
"Damian Burrin" <bur...@nospamntlworld.com> wrote in message
news:1SMie.9650$yY4....@newsfe5-win.ntli.net...
>> Do the halfords kits come with woven glass cloth? I looked at one but it
>> had CSM and polyester resin in it :(
>
> The Halford kits (Dave's i think they're called)with the glass cloth are
> fine for just glassing fins, i personally used the halford kits (the Daves
> ones again) that has the mat rather than cloth and layered two or three
> strips over the fin fillet.
The main problem I can see with using CSM is your rocket ending up looking
like the underside of a bath! If they come with cloth then I don't see why
they shouldn't work - if you can get glass cloth locally by the metre and
you want to do more rockets with it then that'll probably work out cheaper.
> I would be very wary of the polyester resin and use epoxy resin instead.
> I've not tried using the halfords glass for doing complete bt's though i
> prefer to use the international stuff that Pete and my local boat yard
> sell.
>
> I do know Chris E has a very cheap per m supplier but the carriage was
> high so only cheap if your ordering 3 or 4 meters worth or could collect.
Ah yes, one thing I should add is CFS's shipping isn't cheap! I ended up
ordering quite a lot of stuff in one go, which is just as well - cant
remember what it all was now though, small fortune anyhow! It was quick
though, in their favour.
Kev Timmins
I'll check out Halfords tomorrow,.
I'll also check out www.freeflightsupplies.
Thanks Mel, Niall, Damian & Colin,
Kev T
p.s
I do have some CF tissue , that I got from Freeflight ages ago, it may well
be suitable as well.
"Mel" <shar...@aol.com> wrote in message
news:1116438884....@g47g2000cwa.googlegroups.com...
Niall Oswald
> Cheers,
>
> I'll check out Halfords tomorrow,.
>
> I'll also check out www.freeflightsupplies.
>
> Thanks Mel, Niall, Damian & Colin,
>
> Kev T
>
> p.s
>
> I do have some CF tissue , that I got from Freeflight ages ago, it may
> well be suitable as well.
That looks like a good site, they've got much lighter cloth than other
places I've seen, which could come in handy for all sorts of rockety stuff -
reinforcing thin balsa fins for example. I'm sure the carbon rods and stuff
could be useful too.
Bob
> Hi,
>
> what's the best type of Glass Cloth & resin for Glassing fins.
Depends on the fin material, which is...?
> Best place to buy online ?
I got some glass from somewhere the other year and was really happy
with the price. Shame I can't remember who they are as I could do with
a bit more... I'll need to see if I can track down a recipt or the bag
the last lot came in.
> Any comments appreciated.
Do you really need to glass these fins, or are you after durability...?
Cheers,
--
bob [at] bobarnott [dot] com http://www.bobarnott.com/
------------------------------------------------------------------------
"Crash programs fail because they are based on theory that,
with nine women pregnant, you can get a baby in a month."
-- Wernher von Braun
Stephen Woolhead
> finish I think that if you're looking for strength going with glass cloth
> is the best way - its about £3 per square metre and 1 square metre will
> cover a lot of rocket. I'm guessing Kev is looking for strength after his
> broken fin.
Please, please don't do this! About the best result you can hope for is
that the nylon will hold the epoxy in place while it sets. For a composite
structure to work the re-enforcement must be stiffer than the epoxy, and
this so isn't the case with nylon. You would get a better result if you
just painted the epoxy on, and we all know what a pointless exercise that
is!
Have a read of this.
http://www.djaerotech.com/dj_askjd/dj_questions/nylon.html
Stephen
Niall Oswald
news:TU3je.2752$hh4....@fe06.news.easynews.com...
> Please, please don't do this! About the best result you can hope for is
> that the nylon will hold the epoxy in place while it sets. For a
> composite
> structure to work the re-enforcement must be stiffer than the epoxy, and
> this so isn't the case with nylon. You would get a better result if you
> just painted the epoxy on, and we all know what a pointless exercise that
> is!
>
> Have a read of this.
>
> http://www.djaerotech.com/dj_askjd/dj_questions/nylon.html
Nice article, one to bookmark for future times when nylon stockings are
suggested as reinforcement I think. I've read elsewhere that epoxy doesn't
stick to nylon very well either.
Darren J Longhorn
<no4...@schtop.bris.com.ac.com.uk> wrote:
>West Systems epoxy is popular - its available in many places that sell
>boat-building stuff.
>
>I bought mine from from CFS fibreglass supplies http://www.cfsnet.co.uk/ but
>I suspect there are cheaper places.
I've been very happy with CFS. For West Systems and other related bits
and bobs.
--
Darren J Longhorn http://www.geocities.com/darrenlonghorn/
NSRG #005 http://www.northstarrocketry.org.uk/
UKRA #1094 L2 RSO http://www.ukra.org.uk/
Peter Fairbrother
> "Stephen Woolhead" <ste...@perfectphase.com> wrote in message
> news:TU3je.2752$hh4....@fe06.news.easynews.com...
>
>> Please, please don't do this! About the best result you can hope for is
>> that the nylon will hold the epoxy in place while it sets. For a
>> composite
>> structure to work the re-enforcement must be stiffer than the epoxy, and
>> this so isn't the case with nylon. You would get a better result if you
>> just painted the epoxy on, and we all know what a pointless exercise that
>> is!
>>
>> Have a read of this.
>>
>> http://www.djaerotech.com/dj_askjd/dj_questions/nylon.html
>
> Nice article, one to bookmark for future times when nylon stockings are
> suggested as reinforcement I think.
Yes, it's interesting.
However I have had good success using pre-stretched nylon stockings and PVA
over light polystyrene foam, for aircraft wings and fuselages, which works
well - I don't know if I'd use it for rockets though!
When a stocking is stretched there is a point where it won't easily stretch
any more, and then maybe the stiffness is maximised. Or something, I'm not
convinced stiffness is the correct term, but whatever, it works.
> I've read elsewhere that epoxy doesn't stick to nylon very well either.
It doesn't, which is why I haven't investigated prestretched nylon/epoxy in
any detail.
--
Peter Fairbrother
Kev Timmins
"Bob" <K11...@gmail.com> wrote in message
news:3f35v4F...@individual.net...
> Kev Timmins wrote:
>> Hi,
>>
>> what's the best type of Glass Cloth & resin for Glassing fins.
>
> Depends on the fin material, which is...?
4mm Aircradt Ply.
>
>> Best place to buy online ?
>
> I got some glass from somewhere the other year and was really happy
> with the price. Shame I can't remember who they are as I could do with
> a bit more... I'll need to see if I can track down a recipt or the bag
> the last lot came in.
>
>> Any comments appreciated.
>
> Do you really need to glass these fins, or are you after durability...?
>
Due to the nature of the cracked fin damage, It needs to be durable. The fin
is way to difficult to drill ouyt & replace without major hassle . It would
be a real PITA.
I'm going to do the trick I've used before, which is to repair the fin with
carbon fibre micro rod pins & milled Fibre reinforced epoxy. The n Glass
over each fin. afterwards. KIts worked perfectly before.
I got some Glass Tissue from Halfords, but Ive already got CF tissue as
well, which I think may be more suitable for the strength I want to ensure.
Kev
John sim
resins to give various strengths and weights of finish. This is where a lot
of aeromodellers get their glass fibre materials from (and some model
retailers).
John Sim
UKRA 1281
Kev Timmins
"John sim" <john...@btinternet.com> wrote in message
news:d6lmnd$cl5$1...@nwrdmz01.dmz.ncs.ea.ibs-infra.bt.com...
Cheers,
I also found http://www.trident-uk.com about the same cost as CFS
I ended up ordering some West Epoxy from them, as CFS couldn't guarantee it
would go out b4 the weekend.
Kev T
UKRA 1383
Kev Timmins
>>>
>> The site given below has a range of glass cloth construction and
>> different
>> resins to give various strengths and weights of finish. This is where a
>> lot
>> of aeromodellers get their glass fibre materials from (and some model
>> retailers).
>>
>> http://www.fibretechgb.co.uk/
>>
>> John Sim
>> UKRA 1281
>
> Cheers,
>
> I also found http://www.trident-uk.com about the same cost as CFS
>
> I ended up ordering some West Epoxy from them, as CFS couldn't guarantee
> it would go out b4 the weekend.
Trident got the West Epoxy to me today via courier..
Oops,
courier obviously did something seriously wrong! On opening the package (the
couriers packing that is), I found one bottle of hardener completely cracked
, leaking into the rest of the main pack.
Sticky icky mess....
mmm. Trident are replacing asap.
Kev T