Glassfibre moulds repairs and panel making.

[Darkspeed]

To add a bit more to the Pro-Am glassfibre tutorial in a separate thread to stop filling up Pauls thread with general moulding and such tomfoolery.

Pauls - thread - http://www.v8forum.co.uk/forum/viewtopi ... &start=120

The second try on the bumper repair turned out a little better and hopefully tomorrow that will sand back as well as Pauls repairs.



I also thought I would try mixing some clear gel and colour - Ral 1028 Melon Yellow which is the same colour as the Strat. and then make up a small test panel for what I am considering for the bumpers to be made in the green moulds.

If this stuff is good enough for the Pro then its good enough for me.



I realise that this is a bit of a departure from air inlet filter plenum but hopefully if you fancied making an air inlet cap etc. that as well as Paul's great advice on how to do it my mishaps mistakes and diversions may be of some assistance.

Clean PVA and a couple of coats of wax - must be getting better with the PVA as it went on a dream.



Mixing up coloured gel is pretty simple - buy some clear buy some pigment from the range of colours and follow the instructions - in this case 15% by weight






Slap it onto your mould

I only did one single thick lumpy coat and 2-3 even coats is the way to go for a good finish which I am sure Paul will cover when he makes the piece when the mould is complete.



I wanted to lay up a panel no thicker than the bumper itself at about 1.5mm but with a decent amount of strength

To be the same bending strength as steel a standard glass composite needs to be about 2.5 times thicker and at that its only 60% of the weight.

I decided to use statin cloth in the laminate as this is stronger than CSM and takes less resin reducing the weight but with better strength




225g matt and 288g stain weave glass and some surface - These will be the components of the laminate



gel/tissue/225/288/225 the glass



This measures at 0.8mm with vernier and should with the resin swell to around 1mm and with 0.5mm of gel give me the 1.5mm panel I am after.



I also wanted to see just how little resin I would need to use to full wet out the panel - The tissue and the cloth take very little resin and the 225 wets out very easy so I measured for 2 x the weight - usually I weigh 2.5 to make sure I have enough but with the brush wicking method from Paul I was certain x 2.0 would have loads to spare as the cloth is typically 1:1.

The cloth weighed around 38g for the test panel - there is a bit of core mat thrown on top of this shot which is for another test.




After the gel had done its things I set to laying up and was amazed at how little resin I use to wet it out - especially the cloth as this just seemed to wick the resin from the CSM as soon as it was laid - I guess as there is no need to break down and binders it just absorbs like a sponge and in no time at all it was virtually invisible. on with the next layer of 225g CSM and wet that out and then on to seeing how much resin I could pull from the laminate with the brush wicking whilst making sure it was all fully wetted.




After working the laminate and wicking out the resin I managed to have quite a bit of resin left in the pot and weighing up after I estimate that I have used about 55g of resin for around 33g of glass or a resin ratio of 1.6



The cloth is really nice to work with very pliable and soft.

Should be in a position tomorrow to see how it tuned out and what sort of strength it has being so thin.

Andrew

[gelmonkey]

Gissa Job

[Darkspeed]

Gissa Job

Wife already has the tea making duty


Strato's boot laminate for panel comparisons - I am very impressed with the even gel and composite thickness.

I had this one made with a lightweight lay up so core was used on the flat panels to put some stiffness in - at about 2.5mm the panel has half the weight of a steel panel for more stiffness with the core.





As can be seen there may not bee much gel under those flash lines.

[stevieturbo]

I seen a post here that was very good...

This guy seemed to pre soak the fibreglass prior to laying it into a mould, again so use of resin was sparse making it lightweight.

Any thoughts on that technique ?

http://www.rodsnsods.co.uk/forum/tech-f ... asy-176826

[gelmonkey]

Holy SH*T
Glad he don't work for me as that is shocking (in my opinion and yes I do like to say that a lot but thats all it is just an opinion)
Firstly the exotherm in the corners would /will be horrendous as there is a lot of glass when all he needs to do is cove the corners with a proper filler powder or even a small radius of crestomer.
Secondly there are two many parting lines and thirdly the glass has been cut square which will probably lead to cracking or stress riser's down the line.
Glass should only be wet out again IMO when you cannot get at the mould in the conventional manner (rermeber the nose section of Mikes slingshot)
Also when you wet out prior to applying it to the mould you have to either physically pick it up with your hands which thins the glass out instantly or with a brush and then the glass slumps down the sides which also thins the glass.
Sometimes there is no other option but for something so simple to laminate he seems to be making hard work of it.

Shutting up now as I could rant for ages and this is not the place for it.
Getting my coat......

[Darkspeed]

Some interesting methods being employed and I am sure they work for the people using them.

I don't think that the wetting out on a bench and sticking lots of little cut patches together would be a way I would be happy with for a panel - even for a mould I would be inclined to tear the sections and wetting out on a bench seems a bit pointless and messy and you can only work in little squares as a large piece would be terrible to handle.

Cutting to size, laying up in the mould or on the former in large sheets torn where required just seems the obvious thing to do and with knowing how much resin you need and then wicking out any excess whilst working the material seems so logical and straightforward.

[Darkspeed]

Well the laminate has hardened off to most of its strength - it will still gain a little more over the next week but I am really pleased with the strength it has now only after 15 hours or so

This layup works out at 2900g per sqm so the bumpers I am making will go from 1500g to around 300g

As these bumpers are mainly decorative I could take out the final 225 and also go with a single thinner gel coat.

For a lightweight panel for a wing or a door skin I think this could be a pretty good laminate providing there were good returns or curves and body lines - for a big flat panel some ribs may be required or some of the core mat which will be test two.

The 288 satin really improves the strength in a panel.

20 gauge steel (0.9mm) is 7.5kg/square square metre - + paint and protection

This lay-up is 2.9kg/sqm and easily as stiff. You could reduce this to 2.5kg/sqm with little effort with thinner gel and getting the resin ratio a little lower.

I think Paul mentioned an Elva project with just Gel/CSM/Cloth and I can see how that would make a really strong thin lightweight panel.

[stevieturbo]

Is the satin more expensive than the normal glassfibre stuff ?

[Darkspeed]

Is the satin more expensive than the normal glassfibre stuff ?

About £7 a sqm

http://www.ecfibreglasssupplies.co.uk/p ... -wide.aspx

[stevieturbo]

Is the satin more expensive than the normal glassfibre stuff ?

About £7 a sqm

http://www.ecfibreglasssupplies.co.uk/p ... -wide.aspx

Is this same sort of thing ? ( ie my local supplier ) I see they do a couple of different weights too

http://www.mbfg.co.uk/woven-cloth-rovin ... oving.html

Or how does Kevlar compare ?

http://www.mbfg.co.uk/kevlar-cloth/1256.html

[Darkspeed]

No woven roving is very different.

http://www.ecfibreglasssupplies.co.uk/p ... -wide.aspx

The satin cloth is more complex weave and handles just like its name suggests. Have a look and read of the different materials and cloths EC have.

For the part I am doing the woven roving would be a good material to employ and half the price of the satin, although saving 15p on material costs does not really calculate

I must have made an error on my measurement above for the thickness of the materials as dry they are actually 1mm thick.

Complete and fully wetted the composite finished at 1.9mm including the gel - I would think the overall thickness of the laminate only was about 1.6- 1.8mm

I am going to make a test with gel/225/288 with just a thin layer of gel and see what happens.


Kevlar - For the price and ease of use you would be better off going the extra 10% and using Carbon. The coloured twills do look nice though

[stevieturbo]

Is Kevlar difficult to use ?

See I'd like to try making carbon panels...the resin infusion looks cool.

But, all the gear is pricey for a bit of DIY messing.

Wet laying maybe not as pretty, but obviously cheaper. And as for most part I'd be painting any panels anyway, the carbon aspect isnt for appearances.

Just trying to find what would be the easiest, cheapest, most versatile etc But the panels do need to have strength

Resin infusion sounds good as the vacuum process would ensure shape contours are pulled correctly....of course painting in a gelcoat prior to any laying should cover that aspect too.

Wet laying carbon direct may not do this ?

Too many options, and not enough knowledge lol

[stevieturbo]

Although would probably add....because the wings bolt on etc, and I've just taken a direct external mould of the shape.
In order to achieve any decent fit from that, certainly around the mounting areas the new composite panel would need to be almost as thin as the original steel panel, otherwise it will make fitting more difficult.

[Darkspeed]

For what it costs to have a play I would lay up a panel using the laminate above.

It will have the same strength as a 20 gauge steel panel and only be twice as thick. It will however be 1/3 of the weight.

I have not used Kevlar - as I have no use of its properties for what I am doing - I have used it in sail shroud lines and bow strings and it never struck me as very user friendly.

For me - I am quite happy employing materials that were cutting edge in the 70's and used to good effect on race cars of that period on my cars today.

Selecting better glass materials - using good wet layup techniques and having a bit of an experiment is good fun and cheap.

If you want strength and stiffness in key area's just use foams and cores.

I may even have some Carbon Free stickers made up - I must admit that putting a little sticker in the mould to emboss the panel appeals to me.

[stevieturbo]

Years ago I had a local place make a bonnet for me, they made it using Kevlar.

Main reason was they could do a single skin which meant only an outer mould was needed.

But it was a good 6mm thick or so, maybe more. It was strong, but as a large flat panel, still wobbly. They probably should have added some bracing
That said it did last a few years before it took flight and got wrecked lol and fault wasnt because of the bonnet itself, an alloy securing pin failed. Although that was in part due to the bonnet flexing at speed fatiguing the pin

It was after that I started looking at making things myself.

The satin weave thing looks like I could leave it thinner easily in the areas that actually bolt on to the chassis, but then add more layers on the rest of the panel for strength.

How does it contour into tricky shapes ? ie part of my mould includes the shape of a chrome trim

ie I want to mould the wing with this chrome trim intact ( and likewise if I make a new bonnet will do same )
Mainly as these chrome parts are no longer available, so at least if shape is integral to the new panel, I can stick some chrome tape over the top to replicate the piece