antonyg
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posted on 29/5/05 at 06:55 PM |
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extending rear arches
Hi, i plan on cutting and extending the rear arches by about 30mm to cover the wheels properly
I have done a search and downloaded a pdf on fibreglassing but it doesnt say anything about extending fibreglass
I understand the basics of what i have to do, but want to know where i can get enough material to do both arches and have some left over (seen a kit
in halfords for £10 but doesnt look like theres enough)
Thanks for your help/advice
Antony
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viatron
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posted on 29/5/05 at 07:08 PM |
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why are you extending the arches? Is it becuaese the offset on your wheels is wrong? If so you may be better off getting another set of wheels.
Extending the arches isnt a really difficult job but messy!! I wouldnt waste your moeny on a halfords kit as you will probably need three or 4 to do
the job. Look in the yellow pages for a local fibregalss specialist who will sell you matting etc by the yard. some bodyshop supply outlets may also
be worth a call. Obviously you will have to fill the joint and paint as well so the cost may well add up more than a second set of wheels once you
have sold the first set.
Mac
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antonyg
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posted on 29/5/05 at 07:31 PM |
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i have considered getting new wheels but dont know what offset the ones i have are
How can i work this out?
If possible i would rather not extend the arches
P.S i considered extending arches because i built chassis to tiger avon spec then decieded not to use their bodywork instead making my own and the
arches i have are 300mm wide and the avon has been designed with 330mm wide arches
[Edited on 29/5/05 by antonyg]
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antonyg
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posted on 29/5/05 at 07:46 PM |
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PCD and offset
just found this link it explains PCD and offset might be useful
http://www.alloyguide.co.uk/PCD.htm
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antonyg
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posted on 29/5/05 at 08:16 PM |
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the offset of my wheel are about et37 and the size is 195/65/14 approx 7" wide
so to move the wheel further inside the arch am i right in thinking i could get slighty narrower wheels say 6.5" with a greater offset ford go
upto et45
so by my calculations this would move the wheel by approx 20mm and i wont have to extend arches
Its amazing what you can find out on the net ,10mins ago i didnt have a clue about PCD and offset
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RazMan
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posted on 29/5/05 at 10:43 PM |
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You might even find a machine shop willing to take some of the wheel hub face off (to increase the offset) but 20mm might be a trifle ambitious.
......just a thought
[Edited on 29-5-05 by RazMan]
Cheers,
Raz
When thinking outside the box doesn't work any more, it's time to build a new box
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craig1410
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posted on 29/5/05 at 10:49 PM |
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Ford Focus Zetec alloys like mine are ET52.5. This has given me the opposite problem - not enough inboard clearance... I'm using 19mm spacers
and longer studs to get back to ET33.5.
By the way, I have spent most of today fibreglassing because I am building a 4" wider chassis using standard width bodywork and am having to
widen it. It is a pain in the a$$ and as mentioned above, messy. Think of all your options before proceeding is my advice.
Cheers,
Craig.
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viatron
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posted on 30/5/05 at 09:41 AM |
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Not building an avon but you may want to post a question in the Avon section about offset, alternatively give sue or jim at tiger a call and ask! they
currentley have some reasonable tyre / wheel deals on offer using Toyo's.
Mac
You could also post at www.tigerownersclub.co.uk and see if any Avon users there can help.
Mac
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carlgeldard
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posted on 30/5/05 at 02:54 PM |
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Antony
6.5" inch wheels with an ET38. Should do you for a starting point. I can lend you a wheel if you want.
Carl
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robby
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posted on 30/5/05 at 07:02 PM |
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extended my arches by 30mm after fannying around for months trying to get wheels to suit. one box, i think it was the larger of two available, did
both wings, then one tin of p38 or p40 (the red one) and they were ready for a skiff of filler and rubbing down. took less than a day, and wish
i'd done it from the start. if you're gonna do it, i can tell you how i did it? did it cos arches didn't suit home made sierra
back end.
[Edited on 30/5/05 by robby]
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craig1410
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posted on 30/5/05 at 08:48 PM |
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Robby,
No problems with cracking then? How long has it been on the road? My experience with GRP repairs/extensions like this using the likes of P40 and
halfords type repair packs is that the repair will crack before very long. If you are going to do GRP work then I recommend you buy the proper stuff
from the likes of CFS or another GRP wholesaler.
To give you an idea, I have just finished joining my two scuttle halves together after widening them and here is what I did:
1. Feathered the edges of the existing GRP to avoid any sharp square edges. Also ran the linishing disc over the original GRP to provide a key.
2. Degreased the old GRP with acetone to remove any wax deposits from the surface.
3. Clamped the scuttle down upside down on an aluminium sheet which had already been covered in PVA release agent. Used some stiff cardboard coated in
PVA to form some of the other shapes.
4. Painted on gellcoat to form the surface of the widened section of the scuttle. A nice thick coat on all surfaces. This stuff dries chemically like
resin not like paint so you can coat it thick.
5. Once gellcoat was set I used resin and CSM tissue as a first layer followed by four layers of 300g CSM. The gap in the original GRP was 4"
but I used a 16" wide first layer followed by 15",14" and 13". By making each layer a little bit shorter you avoid creating a
stress line. Each layer was consolidated with a ridged roller and stipled into the edges. the result feels very strong and shouldn't need much
fettling to get a nice smooth paintable surface.
Of course I'm no expert on GRP and there will be other's out there who would no doubt do things differently...
A couple of points to note:
Gellcoat cures tacky in the presence of air so the finish surface needs to be inside the mould to exclude air while it sets. Alternatively you need to
add wax to it (2% usually) to make it dry without the tackyness. This is called flowcoat.
Make sure you have enough temperature in order for the GRP to cure properly. My garage was about 16degC yesterday and this wasn't enough (20-30
needed). My gellcoat was still wet after 90 minutes. However once I played the fan heater under the mould to gently raise the temperature (not too
much) then it cured great. It's not such a problem with the resin and GRP as the greater volume of it generates its own heat during the curing
process. Don't be tempted to just add more catalyst to speed up cure times in cold conditions as you may cause the batch to fail to cure
properly.
Cheers,
Craig.
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robby
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posted on 31/5/05 at 07:52 AM |
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hi craig, i think you're a bit more advanced than me! used to be a passenger on a sidecar outfit, so based my work on repairs on the bike! dunno
how long they'll last cos i'm no on the road yet... took 5 mins
to type this... you must have been there for hours!
[Edited on 31/5/05 by robby]
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craig1410
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posted on 31/5/05 at 08:57 AM |
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Robby,
Didin't take me long, I'm an IT Consultant and thus a fast typist... (That took about 3 seconds btw!)
Cheers,
Craig.
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NS Dev
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posted on 31/5/05 at 12:38 PM |
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As Craig said, if you do need the fibreglass stuff, get it from CFS. They are superb, and the price is a lot less than you would think!
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antonyg
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posted on 31/5/05 at 04:53 PM |
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does anyone have a web address for CFS or a phone number please
Thaks Antony
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craig1410
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posted on 31/5/05 at 07:35 PM |
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Hi,
Website is http://www.cfsnet.co.uk
Address:
CFS Fibreglass Supplies
United Downs Industrial Park
Redruth
Cornwall
TR16 5HY
Telephone: 01209 821028
Fax: 01209 822191
Email: sales@cfsnet.co.uk
They really are first rate for service and the prices are very good. Watch out for the price breaks on larger quantities, it is only a comparatively
small increase in price to get for example a 5Kg can of resin compared to a 1Kg and you always need more than you think...
I got resin (catalyst comes free), 300g matting, tissue, white gellcoat, acetone (essential!), resin brushes, paddle roller, industrial marigold
gloves, PVA release agent, special hand cleaner. I should have also got some wax to convert the gellcoat into flowcoat as and when required and some
mixing tubs and measuring jugs/syringes etc. Oh and I also got some 3" thick PU foam blocks to make a bonnet bulge out of.
Cheers,
Craig.
[Edited on 31/5/2005 by craig1410]
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antonyg
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posted on 1/6/05 at 04:36 PM |
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just been adding up what i need from cfs to extend arches and nosecone a lot cheaper than i thought only about £40 for all materials
so whe its done i will try and post some pics
Thanks for all the advice
P.s i've also talked myself into getting some new wheels aswell sen some cheap ones on ebay
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