Complex fibreglass moulding :: Triumph Torque

Moordale Motors

Welcome, Guest.
Please login or register.
Complex fibreglass moulding
Forum Login
Login Name: Create a new account
Password:     Forgot password

Triumph Torque    Chit Chat Boards    Technical Chit-Chat  ›  Complex fibreglass moulding
Users Browsing Forum
Alex, HNJ1N and 14 Guests

Complex fibreglass moulding Print
1 Pages 1 Recommend Thread
Jonny-Jimbo
August 10, 2017, 9:43am Report to Moderator

Club Member
Posts: 4,909
Posts Per Day: 1.23
Hello,

Does anyone have some pointers on how to take a complex mould of a vehicle component? Basically, I want to make a fibreglass mould of a BMW E30 dashboard for the race car I'm building. I've found a dash that is past being any use in a road car (they tend to crack over time).

They are foam over metal pressing construction, so the surface isn't 100% stable, but I hope it's firm enough to take a mould from. My intention is that I just really need the top 'skin' and drop face of the dash, but the lower section and internal bits aren't needed - I will make up brackets etc to mount it into the car after the mould is made.

Basically, this is what the dash looks like, except obv right hand drive, not left.



What would be the best was to take a mould of something so complicated with all the complicated shapes etc?

I'm hoping to make a mould strong enough to use at least say... 5 times, so I can make some and sell them on to help pay for the costs of producing the mould.
My intention is to fill the vent holes etc so when the dash comes out of the mould it will be a 'blank' so that I can then just cut out the bits I need to (which is basically just the instrument cluster hole in my application).

Anyone well experienced with fibreglass moulding? I've made fibreglass parts when I was at Ginetta, but never had to make a mould of anything....



62 Vitesse 1600 - Slammed & modified
67 2000 - Fitted with 2.5 o/d - 2012 RBRR, 2015 Essex Rally, 2016 HCR, 2016 RBRR
67 2000 Estate - Dormant
70 Herald 13/60 - First car, many bits
77 CZ 125 Sport - 70 miles on the clock
77 Kawasaki KM90 - Shop hack
81 Yamaha DT125 - Many bits
88 Ginetta G4/4 - Dead
88 BMW E30 320i - For Sale
89 Citroen AX GT - Rally car!
90 BMW E30 318iS - Building to FIA spec
90 Mazda Eunos 1.6 - 'Popeye'
93 BMW 530i - Donor
95 BMW E34 540i - 4L V8
Logged
Private Message
Howard
August 11, 2017, 8:10am Report to Moderator

Club Member
Posts: 953
Posts Per Day: 0.27
I used to watch my father make GRP molds and that looks like a serious challenge to copy. Some how you are going to have to make a GRP mold in sections which can be separated to create a workable female mold. Each part of the mold is going to have to be easily lifted away from the dashboard so you are going to have to make a series of thin separators cut & sanded to very closely match the profile of each section. Use plenty of release agent on the original and then get ready to have fun

If you are only after a single dash, you could try making a mould from Plaster of Paris in sections with suitable reinforcement (coarse weave cloths, scrap timber etc?) then assemble, smooth & polish the inside. Apply release agent liberally then lay up the GRP in the usual way, but break the mould to release the new dash when it has set.





Le Mans 2007, 08, 09, 10 & 11
RBRR 2008(DNF), 10, 14, 16
10CR 2009, 11, 13, 15
Logged
Private Message Reply: 1 - 9
davidb5964
August 11, 2017, 8:38am Report to Moderator

Club Member
Posts: 173
Posts Per Day: 0.31
Hi Jon
Happy to chat when you are about. I used to make competition slalom kayaks and made many a plug and moulds but as Howard says it is an awful lot of work. I stopped when I became allergic to fiberglass and ferns for some reason!
Dave
Logged
Private Message Reply: 2 - 9
JohnD
August 11, 2017, 11:30am Report to Moderator


Posts: 6,687
Posts Per Day: 1.51
JJ,
The secret is to make the mould in a  number of sections, so that each can be lifted from the original, seperately.
To do this place 'fences' on the original, to break it up into the sections.    A 'fence' is a length of thick card or alloy, fixed at right angles to the surface of the original, if necessary with pop-rivets, as the fence needs to be rigid, and with any small gaps between fence and original filled with Plasticene.
Then construct the mould in stages, laying up the GRP against the fence , and then removing the fence before you lay up the next part.
Before removing the mould parts, you then drill register holes through both layers of the fence part of the mould.
Once the original is removed from the mould, then these holes allow the mould to be bolted back together again, forming an exact, negative model of the original, so you can take your copy, and remove the mould in the same way.

The fences add a lot of strength to the mould, but any wide panel needs stiffening.  This is done, not by merely adding layers of GRP, but by laying ribs across the panel.     These can be Rolled Up Newspaper!    A layer of GRP over the RUN provides a stiff rib without the weight.

All those holes in the original need blanking off, unless you want to make the process VERY difficult!    This is best done with brown parcel tape, which has the useful property of not sticking to GRP resin!

I made a GRP roof and doors for Silverback this way.   Blanking off is best shown by this picture of a completed door, made in two section from two moulds, and glued together with GRP.  The holes seen are cut after construction - the original was holeless, all the gaps being filled with card and tape.
The roof was made in one piece, from a seven part mould.  Below is a pic of the complete mould, bolted up and ready to take the GRP of the copy.   You can see the ribs across the roof panel,  underneath, through the clearish resin.
John



This post contains attachments; to download them you must login.



Serial Vitesse racer.

Old Blue.  1995-2001
Silverback. 2001-2007
SofS. 2007 - to date.

Logged Online
Private Message Reply: 3 - 9
Jonny-Jimbo
August 11, 2017, 11:45am Report to Moderator

Club Member
Posts: 4,909
Posts Per Day: 1.23
Yup - my Ginetta G4 bonnet mould is in two pieces - but I didn't make the mould, only laid up the glass to make the new ones.

The thing I wasn't sure on was what to use as separators to get the different sections. If I can, I'd like to not damage the donor dash as it may come in useful down the line to someone else.

I should be able to find some aluminium to make the fences though... the big dip by the glovebox end in the top of the dash I'm not fussed about retaining, so that can get filled with something too. Maybe even use some of that expanding builders foam sanded to shape and then smoothed off with some polyester filler... Although that would make the donor dash unusable... Still, the dash is cracked so not ever going in a show car etc.

Thanks for your help and photos John, very useful.

Dave, this project is a little down the line (I'll finish your Herald first!), but if you can lend some hands on advice that would be great.


62 Vitesse 1600 - Slammed & modified
67 2000 - Fitted with 2.5 o/d - 2012 RBRR, 2015 Essex Rally, 2016 HCR, 2016 RBRR
67 2000 Estate - Dormant
70 Herald 13/60 - First car, many bits
77 CZ 125 Sport - 70 miles on the clock
77 Kawasaki KM90 - Shop hack
81 Yamaha DT125 - Many bits
88 Ginetta G4/4 - Dead
88 BMW E30 320i - For Sale
89 Citroen AX GT - Rally car!
90 BMW E30 318iS - Building to FIA spec
90 Mazda Eunos 1.6 - 'Popeye'
93 BMW 530i - Donor
95 BMW E34 540i - 4L V8
Logged
Private Message Reply: 4 - 9
JohnD
August 11, 2017, 5:30pm Report to Moderator


Posts: 6,687
Posts Per Day: 1.51
JJ,
As you can see the eventual copy was very light, 9kgs when the OE steel was 30kgs.    But also much, much stiffer.   A metal one distorts under its own weight.  The GRP one could not be twisted between two strong men.

The secret is space!    Like the ribs, an enclosed space between layers of GRP is enormously strong, like an RSJ is very nearly as strong as a solid bar, but much lighter.    I used paper honeycomb, but polyurethane foam can do the same and is more flexible.    You'll often find it inside thin skins of OE interior trim, and can be used in your copy.   Disadvantage - it absorbs resin, and can get very heavy.     A thin coat of resin will seal the surface, and prevent a second one soaking in.

John


Serial Vitesse racer.

Old Blue.  1995-2001
Silverback. 2001-2007
SofS. 2007 - to date.

Logged Online
Private Message Reply: 5 - 9
GT64fun
August 21, 2017, 10:27am Report to Moderator
Club Member
Posts: 111
Posts Per Day: 0.04
Hi Jon

This might be a useful link for you. Based on a 'production standard' mould, but the principles are all there.

https://www.youtube.com/watch?v=keBwRhkfuOQ

Regards

Ian F  
Logged
Private Message Reply: 6 - 9
JohnD
August 22, 2017, 8:49am Report to Moderator


Posts: 6,687
Posts Per Day: 1.51
Ian,
A three part mould for an air box?  Pshaw!  Please read my post No.3 again.   That roof's mould has SEVEN parts!


JJ,
That dip over the glove box (on the right?) should not be a problem, as the sides are sloping inwards and the mould, and eventually copy, will just lift off.  The original would have been made in a mould, so that depression must have pulled out, and will from your mould.     More,  a careful inspection may show flash lines where the original moulds came together, which will show where to place the fences when you make a mould.    
I realised after a while in making my roof mould that the number of mould parts corresponded with the number of pressings that were welded together to make the original.   This was because a pressing is made in a mould-equivalent, out of which the pressed panel must fall, without getting stuck.    The fences ran along the joins made when the roof was assembled.    
This can be a useful guide when 'reverse engineering' a part by copying it.

John


Serial Vitesse racer.

Old Blue.  1995-2001
Silverback. 2001-2007
SofS. 2007 - to date.

Logged Online
Private Message Reply: 7 - 9
Jonny-Jimbo
August 25, 2017, 4:22pm Report to Moderator

Club Member
Posts: 4,909
Posts Per Day: 1.23
I've just posted about this project on a BMW E30 group, and the response has been tremendous! Looks like it might be worth pursuing after all... everyone wants carbon fibre though!


62 Vitesse 1600 - Slammed & modified
67 2000 - Fitted with 2.5 o/d - 2012 RBRR, 2015 Essex Rally, 2016 HCR, 2016 RBRR
67 2000 Estate - Dormant
70 Herald 13/60 - First car, many bits
77 CZ 125 Sport - 70 miles on the clock
77 Kawasaki KM90 - Shop hack
81 Yamaha DT125 - Many bits
88 Ginetta G4/4 - Dead
88 BMW E30 320i - For Sale
89 Citroen AX GT - Rally car!
90 BMW E30 318iS - Building to FIA spec
90 Mazda Eunos 1.6 - 'Popeye'
93 BMW 530i - Donor
95 BMW E34 540i - 4L V8
Logged
Private Message Reply: 8 - 9
JohnD
August 26, 2017, 6:14am Report to Moderator


Posts: 6,687
Posts Per Day: 1.51
Real CF needs an oven to cure the resin, but you can get lookalike material to go in the gel coat.  Good enough for BMW!

John


Serial Vitesse racer.

Old Blue.  1995-2001
Silverback. 2001-2007
SofS. 2007 - to date.

Logged Online
Private Message Reply: 9 - 9
1 Pages 1 Recommend Thread
Print

Triumph Torque    Chit Chat Boards    Technical Chit-Chat  ›  Complex fibreglass moulding

Thread Rating
There is currently no rating for this thread
 


Powered by E-Blah Forum Software 10.3.5 © 2001-2008

Latest Blogs-
King Rat Racing

18th September 2017 7:47pm gmt
Club Triumph 10CR
Paul Lewis

18th September 2017 11:45am gmt
The trip ‘oop North’….
more blogs...
Next Group Meetings-
Shropshire Wednesday 20th September 19:00
West Midlands - 2nd meeting Wednesday 20th September 20:00
Southern Area 2nd meeting Thursday 21st September 20:00
Nottingham Monday 25th September 19:00
Essex Tuesday 26th September 20:00
Cheshire & Staffs Wednesday 27th September 19:30
Coventry & Warwickshire Wednesday 27th September 19:30
Northern Ireland Wednesday 27th September 20:00
Worcestershire Wednesday 27th September 20:00
more local groups...
Upcoming Events-
CT Three Counties Rally
24th September 2017
Chelmsford MC Priestley Rally - 12 Car Rally
29th September 2017
CMC Halloween 20/20 Rally
28th October 2017
CT Essex Winter Rally
19th November 2017
CMC Mince Pie 12 Car Rally
24th November 2017
BCC Santa Rally
10th December 2017
more events...
For Sale-

1970 1300 Blue 53,000 miles. unused in dry garage 26 years. No rust plastic still on doors some spares, workshop manual, handbook. Offer for good home wanted. For more information 07547142606 Croydon

Wanted-

Herald Britax Weathershield Sun Roof, complete please. Bob Angell robertvangell1@ btinternet.com King’s Lynn Norfolk

Original Vitesse 2L Brake master cylinder, suitable for rebuild to convert my Herald.Pm Steve P on the forum or e mail prismsecsys@ btinternet.com

more adverts...
CLUB TRIUMPH the Club for all Triumphs
© Club Triumph Ltd MCMXCVI - MMXV