Roman

Fibreglass, Carbon Fibre, Paper Mache - The composites chat thread

Recommended Posts

Hey peeps, I have a fibreglass spoiler I want to make a copy of and widen at the same time (It's about 1300mm I think and I need about 1600mm).
What would be the best way to do this?
It's uniform enough so was thinking I could take a mould off each end slightly longer than half to get the overall length I needsp1.jpg.99deaad390caf8d862c7ae42322f3bc3.jpg

Then I thought I could take those moulds, tape off the area on the car where they'll sit and use some clay to get the fit nice then take a single mould off that to then produce the final piece.
sp2.jpg.3ae1dcea47cb77762319561f6e498bae.jpg

Is this the way to do it? Any recommendations for materials to use?
Should I just pay someone to do it so I don't spend the same amount on a shitty attempt?

  • Like 3

Share this post


Link to post
Share on other sites

That half half overlap idea sounds pretty sweet I reckon!

And you should definitely do a shitty attempt, will be awesome

Definitely watch some of the video tutorials on mold making etc from that link posted earlier from Carbon Fibre guys, a lot of good tips there that will apply to fibreglass for a spoiler. 

EDIT: these guys
 

 

  • Like 1

Share this post


Link to post
Share on other sites

Hi @kicker it sounds like you have made that too complicated (just my opinion however!)

Making molds is great id you want either a part that is absolutely as light as possible OR if you want to make more than one.

Id just cut your wing in half, cover the back of your car in a tidy layer of duct tape (has a release aid on it so the epoxy wont stick), affix the wing into place and then fill the center section with whatever you want (id go with clay or blocks of foam.. not the spray foam).

Grind the center section beside the clay so that it tapers feom paper thin to full thickness over around an inch, then smash on multiple layers of fiberglass and resin untill its thick and strong.. then pop the whole lot off, peel out the clay or disolve the foam and BOOM.

another good trick with ill fitting spoilers is to cover the area with duct tape then put a layer of body filler on the bottom of the spoiler where it touches the car.. smoosh it down on the car into place and then pop it off for a sand and tidy when cured. You end up with a perfect fit between body and spoiler.

  • Like 1

Share this post


Link to post
Share on other sites

I made this air filter adaptor foe my scoot today. Was going to have david print me one buy that would take days.. this took around an hours labour. Not pretty but functions like it should.20180303_193105-1209x1612.thumb.jpg.946934d570163b0729d57507ae3aad47.jpg20180304_102804-1209x1612.thumb.jpg.7e645cf84d007651d23508b8662c8e0d.jpg20180304_102845-1209x1612.thumb.jpg.57ebf4565fed73cc7f7327164d286244.jpg20180304_104206-1209x1612.thumb.jpg.4159db6233a431a769ef88433429d9f8.jpg20180304_144627-1209x1612.thumb.jpg.a7d2c24ccf224c00b7e71b3a76dddaf4.jpg20180304_145628-1209x1612.thumb.jpg.110a64ff42c31660e2d978d52322d134.jpg

 

  • Like 7

Share this post


Link to post
Share on other sites
18 minutes ago, flyingbrick said:

Hi @kicker it sounds like you have made that too complicated (just my opinion however!)

Making molds is great id you want either a part that is absolutely as light as possible OR if you want to make more than one.

Id just cut your wing in half, cover the back of your car in a tidy layer of duct tape (has a release aid on it so the epoxy wont stick), affix the wing into place and then fill the center section with whatever you want (id go with clay or blocks of foam.. not the spray foam).

Grind the center section beside the clay so that it tapers feom paper thin to full thickness over around an inch, then smash on multiple layers of fiberglass and resin untill its thick and strong.. then pop the whole lot off, peel out the clay or disolve the foam and BOOM.

another good trick with ill fitting spoilers is to cover the area with duct tape then put a layer of body filler on the bottom of the spoiler where it touches the car.. smoosh it down on the car into place and then pop it off for a sand and tidy when cured. You end up with a perfect fit between body and spoiler.

There was one detail which I probably should have included, the spoiler isn't mine so any process I follow has to not damage it but you make a good point and buying one to chop is an option I hadn't really considered. The mold making is an extra fuck around, my main reason for it was to keep my freehand work to a minimum as I want it to look good :)

  • Like 1

Share this post


Link to post
Share on other sites

Similar to kickers question, if you make a mould of a wing like that, it would need to be open on the underside of the wing to remove the mould (if you lay the matting on the outside of the mould). How would you go about making a lip or flange around the bottom so it can be attached to a boot lid?

Completely enclosing the mould would give a really nice flat base to stick it to the boot, but then you either need to cut the part to remove the mould, or leave it in there.

I guess you could do an inverse mould, laying the matting inside the mould, but then the issue still remains, if it's hollow, how do you get a nice solid flat base?

  • Like 1

Share this post


Link to post
Share on other sites

Depending on your patience levels check out parts 1 / 2 / 3 of this. 

In this case a 3 piece mould 
 

 

 

Share this post


Link to post
Share on other sites

Most aftermarket wings that I see (like TRD AE86 wing for example) are made so that its just a single piece with no "under side".

Only the perimeter attaches to the car.

But obviously style of wing allows that to be possible or not.

Share this post


Link to post
Share on other sites

Doing a quick Google I can see why the trd wing doesn't have a base, looks like it's designed to attach via the flat section protruding from the outside if the wing. 

Basically, I'm looking to reproduce the sd1 vitesse wing, but It attaches to the boot lid from the underside of the wing. 

Will watch that video tonight but suspect a multi part mould will be the go. 

  • Like 1

Share this post


Link to post
Share on other sites

You'd almost get away with just making a wing out of expanding foam and bog for the rover / probably spam

  • Like 1

Share this post


Link to post
Share on other sites
40 minutes ago, ajg193 said:

You'd almost get away with just making a wing out of expanding foam and bog for the rover / probably spam

That's a nice touch - Using actual Rover factory fabrication techniques.

  • Like 4

Share this post


Link to post
Share on other sites

Rover didn't have money for such fanciness. The original wing is a slab of moulded rubber with a steel plate in it (for the mounting studs). It weighs bloody heaps, and because Rover, the steel plate rusts from the inside out. 

  • Like 3

Share this post


Link to post
Share on other sites

The biggest thing is to be creative and inventive. It pays to be lazy and find the easiest way.

Eg..  if your wing needs to be two part and you need the wing to have a lower surface- why not use the car itself to work as that surfaces mold

Share this post


Link to post
Share on other sites

It wasn't just Rover. I've found early BMW spoilers to be the same construction technique.

 

  • Like 1

Share this post


Link to post
Share on other sites

I just removed the "do not remove this powder from the resin mix or the machine will instantly lock up " powder from the resin and found the machine actually runs better. Short beam loading tests indicate an increase in strength of 25%, even with 50% more filler added to the resin. Who'dathunk that two mould release agents used at same time would be redundant?

 

/guys in the factory firmly believe that liquid wax is only added to make the surface shiny and isn't a mould release even though the bucket says it is

  • Like 1

Share this post


Link to post
Share on other sites

i cant see the context of what your meaning however liquid wax / wax in styrene solution is added (to polyester and vynlester atleast) due to it not curing at the interface with air, not as a release agent-

the idea is the wax allways wets the surface enough to stop the air touching the resin directly, if you use unwaxed resin in open layup the open side stays sticky forever, in closed molding i have not seen a perceivable difference in surface finish with or without at the approx 0.5-1% (we) use it in

im not very familar with epoxy - may be a diffirent story

Share this post


Link to post
Share on other sites

This is pultrusion using polyurethane resin, the wax I'm talking about is INT-PUL 24, an internal mould release agent to get the part sliding through the die nicely.

 

The powder I removed as Zinc stearate.

 

The only reason they used Zinc stearate as far as I can tell is because they have always used it. They used to get reasonably frequent lockups with the old recipe (different filler added to the resin) and occasionally they'd forget to add the Zinc stearate powder, so they'd blame the lockup on that.

New filler seems to work perfectly fine without it, but old barry running one of the machines in the factory still isn't convinced of science

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now