African Muscle Cars - Forum

Hi to all members. I need a step by step guide to make a mold of the 1969 Ford Mustang scoop. Any advice will help.
Rassie.

My 69 GT and 1970 Mustang had the same scoop.
Rassie.

You want to build it from metal or plastic?

Hi Barry I am not sure? The scoops will be fibreglass.
Rassie.

Did a direct copy and paste with link back. Not everybody is registered there.

Ok, so you've played with some glass and have your technique down, now lets try getting it in the right order. Don't skip any of the steps, unless you are certain you are ready to.

Step 1.
Starting with your base.
Sometimes, if using mold release/aluminum-foil/tape/etc... you wont need a base material to achieve a certain shape. If there is no shape present, your material can range from fleece, to spandex, to cotton, to basically anything with elastic properties. You will completely soak this material in Fiberglass Resin and nothing else. Not fiberglass jelly, not body-filler, not milkshake, only fiberglass resin.

Step 2.
Depending on if you have a curved or flat surface, your fiberglass material may differ. If your surface is nearly, or completely flat, you can save a lot of time with weave(cloth) mat. Weave-mat is made of up long strands of interconnected fibers, which is what gives it its name. If your surface is not remotely flat, and has a lot of curvature, chop(strand)-mat will be your material of choice. Chop-mat looks like a sandwiched, random, hairy collection of short strands. Chop-mat will change its shape, simply by how you apply it.

Step 3.
Repeat step 2.

Step 4.
Repeat step 2.

Step 5.
Repeat step 2.

Keep applying full layers, until the desired thickness is achieved (anything less than 3 layers is asking for trouble, most people go with 6-7 and if you're using a sub like a 12w7, you may want to look into the range of 12-15)

Step 6.
Sand until major issues are corrected.

Step 7.
Apply body-filler. You can use whatever you are comfortable with. I like to use gold/premium, but then again, who doesn't. The cheap stuff will work fine, if you get the hang of it. Apply with spreader-knife (plastic is best, because you can bend the spreader after the body-filler is dry, and it will detach itself).

Step 8.
Sand body-filler. Repeat step 7.

Keep repeating until general shape is there. Do not go too thick with body filler or it will crack. Thicker than 1/8" is not acceptable.

Step 9.
IF NECESSARY apply milkshake. This is a mixture of body-filler and resin. Basically, super-strong topcoat of body filler, which tends to fill all pinholes quickly. Do not rush this step. Do not forget to use BOTH hardeners. This should be thought of as more of a high-build primer (minus the paint) than body filler that goes on easy. This will not solve all of your problems. Some times this step isn't even necessary.

Step 10.
Sand and prep for paint.

Hope this helps.

Rassie - sorry misunderstood . Thought youwere asking about the scoops, not the moulds.

Check out NCS or Cray Valley's websites. They both have info on basic laminating.

Prep your plug (pattern) by getting it to the best finish possible - well cured 2K is ideal. Apply Ramwax (other other wax release) to a haze, let dry & buff. Do this 6 times.
For peace of mind I'd now use PVA release - applied with a sponge. This will screw up the surface finish, but vastly reduce chance of hanging up. You could always pull more moulds leaving out the PVA (must be washed off and reapplied each time) by about the 3rd or 4th when the plug is seasoned. Apply one more layer wax for each pull.

When the PVA is dry mix your gelcoat and catalyst. Make sure it is very well mixed but don't use a machine - this will break the thixotropic state.
Apply gelcoat with a good quality brush using long flowing strokes. If the brush is dragging you've got too little and may lift the PVA. The idea is to create a skin about 0.5mm - 0.6mm thick. Sometimes there will be spots/brush lines that won't cover and you'll need a second layer. Try to avoid any lumps.
Allow the gelcoat to set - ie "dry" enough that it doesn't transfer to you finger. Don't use heat/fan to speed up the cure as it will drive off styrene and cause undercure. It will remain tacky as it is unwaxed. Check the entire surface as it is common for the catalyst to not be evenly dispersed.
Undercured gelcoat will wrnnkle on application of next layer, but for best results the gelcoat must not stand for too long before next layer. Certainly not more than 24hrs.
Once you're happy with the gelcoat you can begin laminating. Pre-cut your cloth/CSM. Catalyse and mixe your resin and wet out the surface. Apply 'glass and dab/stipple with the brush to get it well soaked. Idea is to use as little resin as possible while elimating all air pockets, bubbles, dry spots.
Allow the resin to gel and exotherm and then apply the next layer. Again if it has stood for any length of time the bond may not be ideal - wipe down with acteone/scuff with coarse sandpaper.

I believe in post curing - will be good to do it on the mould. After all exotherm heat has gone place the entire article in oven at 80*C for five hours. It may be a good idea to clamp it to the mould to stop it pulling away. Polyester resin shrinks on cure and your shape as well as thicker/thinner areas will determine which way it wants to pull. Post curing on the plug, (and post curing your scoops in the mould) will reduce this vastly. Also the better the level of cure (less styrene remaining) of your mould, the less chance of hanging up.

Sure you have enough info now whether it's moulds or speaker enclosures you want to make!!


PS - I'd rather have a metal scoop than a plastic one

Very interesting topic guys..

Barry, how would you go about making a metal scoop? Surely, it can't be easy..

Some good metal shaping stuff here...

All the principles you need are in these videos...

Jesse James Metal Church

#1 http://www.youtube.com/watch?v=6Ir0A2VRyYg 6:58

#2 http://www.youtube.com/watch?v=zFWjkGN_EGY 10:10

#3 http://www.youtube.com/watch?v=w7_cCWxQR2I 5:19

#4 http://www.youtube.com/watch?v=lJB2hCJ_zQM 8:42

#5 http://www.youtube.com/watch?v=bBplX...eature=related

Steve - Jesse shows some great stuff & all, but he is working with about $400 000-00 worth of equipment.
Check out www.allmetalshaping.com - a guy called Johnny Arial shows how to make the same tank with handtools.
Also check out www.metalmeet.com. Unfortunately a LOT of info was lost in a crash recently.

There is an excellent DVD by a guy called David Gardiner at www.metalshapingzone.com - worth every cent.

Tony there actually isn't that much shape in a scoop. Kind of hard to explain how I'd make it, but there are only a couple of processes: Stretching,shrinking, welding & bending. It would be a combination of these
Come do a course & I'll show ya

Hi Guys, thanks for the help, we had no connection for a few days. I will use the advice and put some pictures.
Cheers
Rassie.