Fiberglass process

[bubs]

Does any one here know of a good online resource of the process of making fiberglass molds for making guards etc?

Or anyone here in brisbane do this

[giantracing]

what do you want to know dude

[short stuff]

try this guy he knows a fair bit about fibreglass so he should know who to see his pretty helpfull
http://www.yellowpages.com.au/onlineSol ... s&z=200021

[bubs]

what do you want to know dude

basicly i need to make some yankie style bedsides off a styleside tub i have here

and i know nothing about fiberglassing

[bubs]

try this guy he knows a fair bit about fibreglass so he should know who to see his pretty helpfull
http://www.yellowpages.com.au/onlineSol ... s&z=200021

thanks I will stop in there after work one day this week

[thehanko]

your basic needs to start with will be:

PVA Release agent
Caribou wax (or similar for polishing the moulds)
lots of wet and dry
tooling gel coat if you want to use the mould alot of times as its harder wearing.
normal gelcoat for production.
basic vinyl or polyester resin is the easiest to use, but wear gloves as the hardener methyl ethyl ketone peroxide is not good for you.

foam squeedgy of paint brush and resin roller.


Its a bit like painting a car in the fact that preparation is the key.

First you make a plug - the same shape as what you want your final product. eg if your making a wheel arch but want to modify it, then take a normal guard cut what you want to remove and build up want you want to build up, you can use any material, i would probably go with welding on extra metal where needed and then car bog to make it the right shape.

get the plug to the same sort of starightness etc that you want the final product. the finish needs to be pretty smooth to ensure your mould releases from it. the prep here is the key to a good mould.

polish it, wax it polish it etc. then put on you PVA release agent as per its instructions.

pre cut your glass - woven glass will bend much easier than chopped strand which is a random pattern.

paint on your tooling gel coat (with hardner mixed) you need to get it thick enough but not too thick. let it dry, give it a light rub back then glass over the top.

I would use several layers of lighter / mid weight woven glass first off to get good contouring, then another 6 or so layers of chopped strand. then you can reinfoce the mould with strips of timber with glass over them to keep it rigid and from deforming. this can be done in several stages letting it dry in between and re sanding to get good adhesion.

let isd set for as long as you can, a few days to let it fully sure will help stop it warping at all.

gently pop it off start at a corner and work it out.

polish it well the polish it well, the better your mould the easier it is to use later. polish it between each product you make in it.

If there is any tripe or fault in your mould, its a painstaking process of filling the faults with tooling gel coat and wet and dry it back.

hope that helps.

[bubs]

its gives me a good starting point on how it works.

thanks

[hilux79]

basic vinyl or polyester resin is the easiest to use, but wear gloves as the hardener methyl ethyl ketone peroxide is not good for you.

I would wear a respirator and goggles with MEKP as well. If you read the MSDS on it you will realize how nasty it is.

Ben.

[fester2au]

This link has some really good insight too but it's pretty much what thehanko said. This one is the steps in a carbon fuel tank but the principals are the same except for the vacuum bagging. If this doesn't scare you off with the prep required for a good result then go for it.

http://www.bayarearidersforum.com/forum ... genumber=1

[Matt_88]

pretty much wat hanko said but with the chop strand and woven, the chop will be easier to wet out first than apply which will make it mould to any shape. Id do 3 or 4 layers of about 600csm than the woven roving and at least another 3 layers of 600 or 450 csm.
Depends how strong and heavy u want the mould!

and if u plan on doing alot id buy in bulk as the materials can be fairly expensive.

also when using catalyst and resin good idea to wear gloves and if ya get some on ya make sure u get it off fairly quickly as it does burn.

cheers

[b_mac]

Also with the MEKP, wash your hand BEFORE going for a piss. Not good for the skin on your knob

Very nasty shit.

Bruce.

[bru21]

Hey mate I have done a fair bit in the past. I have 20lt of polyester resin I am wiling to sell fro a reduced price.

FGI is the supplier they have online information.

making moulds really sucks, its worth paying others to do.

the raw materials are dear - about $8 pre square of glass which goes no where and resin is dear.

I got a price to make a bonnet / fender mould for gq. $1500 for mould and $700 per pull.

there is a really good tv show in the us that has trophy truck building etc on in. there is an episode on making moulds available online. I will get the link tonight. pm me if i forget.

cheers Justin

[bubs]

there is a really good tv show in the us that has trophy truck building etc on in. there is an episode on making moulds available online. I will get the link tonight. pm me if i forget.

cheers Justin

cool, let us know how you go.

I found out my dads best mate from high school did fiberglassing for 20 years so I am going to go see him about it.

[blurredvision]

Here is a link for a slightly rough way of doing them.

http://www.race-dezert.com/forum/showthread.php?t=46841

Hope it helps.

[mud guts]

You Tube is good, heaps of stuff. Problem is not getting distracted, i always end up watching fourbys crawlin!!!

[Navara04]

CSM should be cheaper than 8 dollars a metre. MEKP will blind you within 10 or so seconds of it getting in your eyes,

PPE goggles, gloves ect
worth buying an eyewash bottle
Cheers

[thehanko]

CSM should be cheaper than 8 dollars a metre. MEKP will blind you within 10 or so seconds of it getting in your eyes,

PPE goggles, gloves ect
worth buying an eyewash bottle
Cheers

glass has gone up a bit in recent times, but dependinh on how much you need you can buy it for f all.

if you need anything from fgi I have an account with them and might be able to hook you up.

[bru21]

here you go chief. look down the list of video;s on the right hand side.

its called Create a Fibreglass Fender Mold

http://www.powerblocktv.com/sites/video/powervideo.php

[bru21]

Found this today:

Moulds are the most important equipment in FRP production, upon which depend surface finish and reproducibility of parts, as well as the efficiency of the shop. They represent a considerable investment in money and time and all methods of prolonging their life should be considered essential before, during and after construction.

Refer to Data Sheets and K & H MOULD RELEASE SYSTEM for information on pattern preparation.

1. MOULD DESIGN

A basic guide is that the mould should be 3 times the thickness of the component part it will produce. This must be modified to incorporate increased thickness for bolted flanges, lifting and cradle fixing points. If sandwich construction is employed, the outer laminate is additional.

It is essential that where a mould has external loads applied to it due to moving around a shop or swinging for accessibility, an external frame must be incorporated so that these loads are not transferred directly to the mould. Sandwich construction is desirable on flat or moderately curved areas to ensure rigidity.

Request advice when using balsa to ensure print-through of blocks is avoided. Avoid the use of woven re-inforcements as they tend to “print-through” and the weave pattern can be seen in every subsequent moulding. The extra strength of woven products is not needed in a well-constructed mould, but if sandwich construction is not employed, it will improve stiffness.

Where the mould is to be split, an up stand is temporarily fitted to the pattern. This is made from plasticine, shaped to the desired contour, or from strip plywood held in position using plasticine or modelling clay. An aid to location of split moulds is to place on the up stand large dome-head upholstery tacks spaced at a suitable distance. These will form recesses in the mould flange. When the up stand is removed and the mating part moulded, a protrusion is formed. Thus on future assembly, the parts will locate together.


2. GELCOAT

To obtain a minimum recommended cured gelcoat thickness of 0.5mm, you will require 0.8 kg of Tooling Gelcoat per square metre of mould surface. Select a colour which will provide a good contrast with the most common colours to be produced.

Brushing viscosity may be used on small moulds but spraying is much superior and less prone to error. Do not make any additions to the gelcoat, particularly of styrene, as this will reduce the mould durability and crazing resistance. Do not apply spraying viscosity gelcoat by brush.

General purpose gelcoats should not be used as they do not have the resilience, chemical resistance and heat distortion level required to resist the hot gaseous styrene which is present during exotherm of parts. This is the main cause of mould surface deterioration.

3. GELCOAT APPLICATION

IMPORTANT - Thoroughly stir the pail of gelcoat before commencing spray-up as settling of pigments and promoters will occur in a very short space of time. Stir the pail and decant the gelcoat quantity required.

Before application of the gelcoat a gel time check should be made. The ideal is to use gelcoat with a relatively short pot gel time to obtain maximum cure. For smaller parts, 10 - 12 minutes with 1½% catalyst @ 25ºC will give a 25 minute gel time on the part. For larger mouldings, such as swimming pool moulds, the pot gel time needs to be approximately 15 minutes @ 25ºC to obtain a working time of 30 minutes.

The gel time check should be made at ambient temperature. Into 100 gm of the gelcoat add and mix 1.5 gm of MEKP Catalyst (1½%). The gel time should be 12 - 15 minutes.

It is pointless to try to make a mould below 20ºC as the gelcoat must gel within 30 minutes on the pattern to achieve good thorough cure. This also applies to the back-up resin, so ensure that the minimum temperature in the mould-making area is 20ºC throughout the mould manufacturing time period. This may involve the use of heating overnight to maintain minimum temperature.

The most reliable system is to use a hand-held pressure pot type spray gun, such as the Binks 230, where the catalyst can be accurately mixed at 1½%. This may be reduced to 1% at high ambient temperatures or increased to 2% at lower ambient temperatures. Do not work outside these percentages.

You can achieve a slow material flow rate and excellent atomisation with the equipment specified, but remember that the gelcoat in the pot is pressurised and thus will gel quicker than in an open cup. Ensure that the plug and material temperatures have all reached 20ºC minimum and test spray a small area of cardboard, etc. to adjust the spray pattern. If a refill will be necessary to cover the area, it is essential to have a spare pot on hand and a helper to catalyse the second mix at the right moment and pass it to the sprayer. The first pot can then be refilled with gelcoat if a third batch is required and the residue mixed into the fresh material, to prevent it gelling on the walls of the pot.


Spray a minimum wet film thickness of 0.6mm (25 thou).

For large moulds, catalyst injection equipment can be used but the risk of fine porosity resulting from unmixed catalyst droplets needs to be considered. Calibrate the equipment carefully to obtain the correct catalyst ratio. The only sure method is to check the gel time of material sprayed into a bucket against several small samples catalysed at varying percentages where the catalyst has been accurately measured.

Ensure that no dust is entering the work area and dust off the plug with lint-free rags. Check the air supply to make sure that no water is coming through and then apply the gelcoat with at least five fine passes. The gelcoat must have time to “breathe” between passes to allow entrapped air and free chemicals to escape. This is possible even with a substantial material flow, but rapid gun movement is necessary to avoid dwelling with subsequent runs. Never apply gelcoat in one pass. It is a sound principle to spray a test panel on a piece of glass, laminex, etc., which can be checked for porosity before proceeding with laminating. It is wise to strip off a suspect gelcoat and start again rather than to make a sub-standard, porous mould.

4. MOULD LAMINATE CONSTRUCTION

Select a resin which has a high heat distortion point, excellent chemical resistance to minimise styrene attach, low shrinkage and excellent physical properties. Normally, this will result in the choice of an isophthalic resin. Vinyl Ester Resin is recommended where very high exotherm is likely in production. Use a wax-free type, unless subsequent laminates are likely to be delayed longer than overnight, in which case use a waxed resin and sand between laminates.

After allowing two to three hours for the tooling gelcoat to gel, apply 0.2mm of resin behind the gelcoat and allow to TACK. It is critical to have a resin rich gelcoat/resin interface. Then apply one layer of 225gm Chopped Strand Mat, followed by one layer of 450 gm Mat. 225 gm Mat will minimise print-through of strand pattern. This thickness of laminate will develop sufficient exotherm to ensure adequate initial cure. Leave overnight.

Note: High performance resins are “stickier” than G.P. types and great care must be taken to roll out all entrapped air, especially in the first layer. A surface tissue may be used behind the gelcoat and helps to minimise strand pattern print-through. However, it may trap air and care must be taken.

Once the first layer is cured, the laminate is then further built up to designed thickness by successive layers of chopped strand mat or with a chopper gun. Ensure that laminates do not develop excess exotherm. Each 2 x 450 gm should be cured before proceeding to the next layer. Ensure that a minimum temperature of 20ºC is maintained throughout this back-up process, applying heat where necessary.

It is essential through the laminating process that a high glass to resin ratio is maintained, to ensure minimal shrinkage and if catalyst injection equipment is used it must be properly calibrated. Avoid the temptation to facilitate wet-out by using more resin, which will increase shrinkage.


5. RELEASE FITTINGS

Where parts are difficult to release incorporate some of the following recommendations:

A) Laminate lifting lugs into the part to enable an evenly distributed load to
Be applied via a hoist or similar device. Use spreader bars, so the part is
Pulled away from the mould.
B) Laminate pipe nipples onto the outside of the mould, drill through nipple
and mould. Cover the small hole with an adhesive tape to prevent ingress
Of gelcoat and resin, then apply water or air through the nipple to assist
Release.

C) Use high density polyethylene wedges to free the edge of the mould and
Follow up with compressed air.

Note: Do not strike the mould with a mallet, as this can initiate star cracking in the gelcoat, which will spread with each subsequent moulding.


6. FINISHING & BREAKING IN

The most important facet of satisfactory mould life occurs when the mould is first made. The mould must be allowed to cure for seven days at 25ºC incorporating post-curing wherever possible, additional curing time may be advantageous.

Ideally leave the new mould on the plug for one week to ensure minimum shrinkage and distortion during cure. Post-curing of 6 hours during this time at temperatures up to 65ºC is desirable if facilities are available, especially for vinyl ester moulds. Test the gelcoat surface for Barcol hardness which should be at least 35 to 40 for best gloss retention.

Now after thorough curing the mould is ready for preparation. Do not use coarse abrasives on the mould surface. If necessary, use 1200 grade wet-or-dry paper with liberal amounts of water. Wash the mould thoroughly with water and allow to dry, then follow with complete K & H Mould Release System.

Experience will enable operators to decide whether PVA is necessary in addition to waxing; if in doubt, it is prudent to apply it for the first 2 - 3 mouldings, after which the mould will have cured considerably reducing the possibility of stickups. Make sure to select a wax which is compatible with PVA. Apply a coat of Paste Wax between pulls for at least the first three parts.



7. SPLIT MOULD OPERATION

When bolting moulds together, ensure that the following points are covered -

a) The flanges are rigid enough to withstand bolt loads
b) Bolt holes are close enough to effect closure of parts
c) Large washers are placed under bolt heads and nuts to prevent crushing of flange laminates

Should gaps occur on a split mould, assemble the parts together with a bead of Dow Corning RTV Sealant 732, screed off the excess and allow to dry. This provides an excellent gap-filling membrane. Alternatively, Scotch tape or modelling clay may also be suitable.

CONCLUSION:

The average life of a mould from a cost amortisation aspect is 200 components, but this may vary both ways depending on the part.

Well-made moulds have produced as many as 1000 parts.

By strictly following the above technique you will have good moulds with very long trouble-free production life. Above all, do NOT be tempted to hurry the process or take short-cuts, whatever the crisis or pressure for delivery from your customer.

[gonfellon]

off subject abit.these guys over here did my flares
and they do abit of all sorts of 4x4 gear
http://www.4wdfiberglass.com/
not bad prices
might be some one over in aussie that does the same all ready
or that what you looking at starting up?

[LuxyBoy]

I wonder what it would cost to get panels made like plane wings where they use thin fibreglass and aluminium sheets sandwiched together
They are super light but also super strong.

[bru21]

I would imagine the cost would be high.

They tend to use epoxy resin for this purpose which is 3x the price of polyester. Several kit cars are made in this manner such as the Birkin ala PRB.

http://www.prbaustralia.com.au/

[turbogu]

heres a thread of a guy in the states making carbon panels for a cobra, later on in it some where he shows the steps to making the moulds, its all the same for glass as well,

http://forums.corral.net/forums/showthread.php?t=660756

the biggest thing with glass or carbon which no one has mentioned ( at least i think they havent) is it isnt really much lighter unless its done properly, as in vacuum bagging it, its the air pockets in the resin that add the weight, vacuum bagging it ( or pressurizing it if your moulds are the other way round) to remove the air are what take the weight out, ( i was told and shown that buy a guy here who makes and sells carbon rowing skuls world wide, think the guy with the cobra mentions it some where to, been a while since i read all his posts)

If you just go and slap some resin on some glass matt and call it a day chances are it will be heavier than what your replacing, get the air out of it and its like you put it on a diet!!!!!!

a few yrs back i spent awhile with a company making some mufflers for Incat Tasmania, they were 40 plus ft long, 20 ft wide and about 5 ft high and over an inch thick, let me tell you months of itchyness and ruined clothes from all the resin, glass is awesome stuff but boy it sucks some times

the muffs went on one of these



http://www.incat.com.au/domino/incat/in ... enDocument

have fun

[bru21]

Air does not add any weight at all. in some cases micro spheres are added to add air and reduce weight.

The vaccuum is used to allow the glass / carbon to wet with far less resin than is normally required. Glas is weak and resin is useless by themselves.

There is a synergistic ratio that is reached between the 2.

Good examples are items like windsurfer masts / batterns etc