How to laminate Girder on Rob shaws 550 yacht.
The girder is made out of foam and has one layer of fibre glass on either side using epoxy resin to combine the two.
MATERIALS NEEDED:
1. A completely clean flat surface (NO GAPS/HOLES). This should be bigger then the girder by 50mm+.
2. EDB240 / Fibre Glass. 3. Perfirated Plastic. 4. Peel Ply. 5. Mesh. 6. Z105 Epoxy. 7. Vaccume Bag.
8. Vaccume Tape. 9. Clean containers. 10. Paint brush. 11. Vaccume. 12. Masking Tape.
13. 8mm Foam 80 density. 14. PPE Gear
STEPS ON HOW TO LAMINATE GIRDER
1. Have a Clean work space. Have all appropriate PPE.
2. Make a long skinny 200mm pocket with the mesh and tape it to the end of the vaccume. This is to help stop any resin getting into the hose (vacume).
3. Place foam on Flat surface keeping in mind the 50mm+ clear space needed around the foam.
4. Place the vaccume tape on the Flat suface 50mm+ around the foam. Leave the paper on the tape.
5. Put Latex gloves on. Pour 4-5 pumps of the Epoxy mixture from the WEST SYSTEM into a clean container and mix for 1-2minutes. It should look one consistant colour. Take a note of what time it is for the pot life of the resin is limited.
6. Now using a paint brush give the side of the foam that is to be glassed a light coat of resin. The foam should be faceing up. Be carefull not to get any resin on the flat surface for it could effect the vaccume tape.
7. Now carefully place the fibre glass ( F/G ) on top of the foam. Now with a paint brush start to saturate the F/G evenly and consistantly with the resin. As the F/G starts to soak in the resin it becomes see through, this is a good sign that there is enough resin and does not need anymore. All of the F/G should be in this state. The resin should not be runny at all.
8. Now place the peel ply on top this should be atleast 50mm+ wider then the F/G. Using the same technique used to coat the F/G, slowly start to work in the peel ply all around the F/G area, you do not need to resin coat to the ends of the peel ply.
9. Place perfirated plastic on the top of the stack and then the mesh these both should be atleast 50mm bigger then the foam.
10. Now with the vaccume bag make a kink 30mm high going foreid to aft threw the centre of the bag or where the centre of the foam is. The vacume bag should be atleast 200mm+ bigger then the mesh.
11. Now slowly start to peel the paper off the vaccume tape at the same time applying the vaccume bag as you go, be sure to make the most of the bag by tapeing it down right to the edges of the vacume bag leaving at leaste a 10mm over hang. Also make sure to run your finger's over the bag and vacume tape constantly till theres no air bubbles between the bag and tape. Make sure that there are no laps for this will kill the air tight seal. However if this does happen pull the bag clear of the tape and place some vacume tape into the lap/gap turning it into a slight kink. Keep going around leaving enough space for the vaccume to fit in.
12. Now place the vaccume in (but not on top of the stack) and start to form a air tight seal around the vaccume hose using the vaccume tape.
13. When you are happy that you have done your best to give a air tight seal, turn the vacume on.
14. Now patiently wait and watch. If the seal is air tight the vaccume will start to suck all the air out off the bag. While this is hapening you need to keep the shape of the 30mm high kink by pinching the vaccume bag up between the two kinks that was previously made. If air is not getting sucked out of the bag it will not tighten fully, so you will need to use your eyes and ears to find the hole / holes. You will know when the bag is air tight when you are unable to pull the vacume bag away from the mould.
15. Leave to cure for 5-7hrs.
16. Now when the resin is fully cured put PPE gear on and you may start taking every layer off bar the F/G. Be very carefully for there may be bits of sharp F/G. Throw all this away bar the vaccume bag as it can be used again (but if you have enough vac bag to dispose it then do so).
17. If there are any excess F/G around the the foam, depending on how much needs to be taken off.
e.g : small amount use sandpaper / lager amounts use the diamond saw to cut this off. Be sure to wear the correct PPE gear when doing so. Be sure to seek advice if you do not know how to use the diamond saw.
18. Now to F/G the other side flip the girder over and repeat steps 1 to 17 again.
MATERIAL'S OUT LINED :
1. Z105 EPOXY resin / Z206 Epoxy hardener : The ratio is 1 part Z206 Epoy and 5 parts z105 Epoxy by volume or weight measurement. The resin and hardener is one of several WEST SYSTEMS and is recommended for use when moderate cure time is desired.
2. EDB240 FIBER GLASS : The E represents the type of F/G. DB Stands for double bias. 240 is the weight of the glass per squaremetre. The purpose of the fibre glass is to strengthen the girder for the girder has to be stiff so that it can withstand the pressure coming from the deck to the hull. When cutting the F/G it is essencitial you use a sharp pair of scissors, this is to reduce the chance of effecting the direction of the fibres. If the fibre directions are altered it may make holes in between the fibres which takes away alot of its assets. Store fibre glass in a safe place for its easily contaminated or damaged.
3. PEEL PLY : Purpose for peel ply is to :
1. When applied to resined F/G it extracts the excess resin. This help reduces the amount of sanding needed.
2. When the resin is cured the peel ply can then be peeled of leaving a nice flat surface on the fibre glass beneath it.
3. When it is applied and the resin has cured it can be left on as protection from contamination.
4. The red lines going down it is so you can make a clear distinction between the F/G and peel ply and makes it easier to be seen when removing.
4. PERFIRATED PLASTIC : The purpose for perfirated plastic is to not only give the F/G a smoother surface but the small holes in it help suck all the the air out when vaccuming and gives the excess resin, somewhere to seep through.
5. MESH : The purpose for the mesh is to help the air suction go all the way around the inside of the vacume bag. If this was not used it would be quite difficult to suck all the air out of the bag. It also helps any excess resin to seep threw.
6. VACCUME BAG : The purpose for the vaccume bag is that when sealed properly, there is no way air can get through, which makes it perfect for getting an air tight seal. It is VERY IMPORTANT that there are no holes in the bag for this will kill the chances of getting an air tight seal, and also makes it quite difficult to find / fix.
7. VACCUME TAPE : The purpose of the Vaccume tape is to give the Vaccume bag an air tight seal to the surface it's applied to. When applying the vaccume tape it's very important that the surface it's being attached to is perfectly clean. eg: If there is excess resin on the surface you choose to apply it to not only would it not stick but the vacume tape will lose its stickyness completely.
8. FOAM : The foam is 8mm thick and is 80 density. Its pursose is to be used as the main mould of the girder.
POSSIBLE WAY TO IMPROVE THIS PROCESS :
A possible way to improve this process is if I (You) could figure out away so that the foam is sitting up right without assistance, the same steps / method could be made via the materials will need to be cut bigger. Both sides could be laminated at once which would save twice the amount of time.
COMPOSITE : Means two or more materials.
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