Progress Thread A Short Shelby Type Hood For A 69 Mustang

[horse sence]

I have been wanting to do this for some time now ,a short 69 Shelby type hood to fit the factory fenders and headlight buckets for a 69 Mustang .I will be starting with my old Ram air hood ,it blew off the car .The center is damaged but i will have to cut that away because the Shelby top is flatter in the middle ,i will be bonding the new top on the old metal hood .This will only be so i can make a mold for the shorter top and to have a solid base for the mold .
I will be using ISO resin /marine resin , to make the molds and the new hood . the new hood will bolt in the factory location and latch as the factory hood also ,it will also use the 69 hood peak molding .

I will be making the top and bottom under bracing from this Shelby hood i bought for another project ..I know another project

I will be setting up the metal hood on my (later on down the line 69 project ).It is a very straight 69 fast back and i have a very good set of 69 front fenders and headlight buckets i will bolt in place on the car to make sure the hood follows the top of the fenders ,cowl and headlight buckets .This will take a little bit because i will have to make 4 molds to get to the finished short Shelby type hood .

 

[horse sence]

I bolted the fenders ,headlight buckets and the cowl vent in place .The hood needed to be bent in several places to make it flush with the top of the fenders,cowl and buckets .It fits very well now .I need to weld some bracing under the hood to make sure it keeps its shape and i will be ready to cut out the center of the hood .

 

[horse sence]

I welded in some 3/4 square tube under the hood ,it is solid .I cut out the center of the hood ,I left about 3 inches of the top around the edges to bond the new top to.
HEY ! No more dents !
I will probably have to cut some of the under bracing for the new Shelby top to set correctly but it will not be a lot .
I should have the top by Wednesday .

 

[horse sence]

I have been trying to find a pic of a 69 Shelby de Mexico and this is the best one i could find that shows the hood .

my new hood will look like this ,only it will have the front scoops like the American Shelby ...And fit a lot better than this one does ! I have been trying to figure out the positioning of the top and how it will set on the short hood .The front scoops look like they run clear to the front of the hood only they do not have the openings ,and the back of the hood looks like it lines up the very same on both hoods. The metal hood is 3 1/2 inches shorter than the American Shelby hood .The hood pin dimples will have to go because they will not work with the stock front fenders ,but the 69 Mach1 pins will work . I will have a top skin very soon .

 

[horse sence]

I made the top skin this morning ,it will stay in the mold until tomorrow but i will set it in the sun today to speed up the curing time . A bit of trimming ,remove and fill in the hood lock pockets and it will be ready to bond to the metal hood .

 

[dennis112]

Jim, Curious as to what you used to make the mold impression of the Shelby hood before adding the glass? What did are you using for a release to separate it from the fiberglass? Wish you had taken a few photos of the process because it's something that I would like to try.

 

[B.erazo712]

That's gonna be a beautiful car. My favorite mustang is the 69' fastback. I'm Jealous!

 

[horse sence]

Jim, Curious as to what you used to make the mold impression of the Shelby hood before adding the glass? What did are you using for a release to separate it from the fiberglass? Wish you had taken a few photos of the process because it's something that I would like to try.

The mold itself is fiberglass .I used the Shelby hood above to make the mold for the top skin .I will go into it in detail when i make the mold for the short hood .

 

[horse sence]

I pulled the top skin from the mold this morning ,trimmed it and cut the hood pin pockets out because they will not work on the short hood ,they will be filled in later before the mold is made .I also cut the 3 1/2 inches off the front of the top skin ,because it is 3 1/2 inches longer than the shorter metal hood .

After making sure the steel hood was level /not twisted ,i ground the 3 inch edge that i left , perfectly clean with a 36 grit disk .I then wet the edge with resin and placed a layer of 2 0z mat on the metal hood .I then wet the mat with resin .My brother helped me set the top skin in place .I then used strips of sheet metal on top of the new skin to help hold down the edge to the steel hood under the top skin and spread the load from the clamps .It just has to set up for a day now and trim the mat that squirted out the edges to the metal hood .There will be a very small amount of body work on the top before i can make the mold ,i had to slide the top skin back 5/8 of an inch to get the front scoops to fit in the top of the metal hood .This left a 1/16 gap down both sides of the new top that has to be filled to meet the edge of the metal hood . As i said before ,this will only be to make the mold for the new hood but it has to be straight enough to paint black as if it were the actual finished fiber glass hood .

 

[candphall]

Now there's a guy with some clamps!

 

[horse sence]

You may call me Jed

 

[horse sence]

I trimmed the top to match the metal hood ,filled in the hood pin pockets and did a little block sanding .The very peak need to be sanded down because it turned up just a bit . I was surprised to see how smooth the top was being bonded to a metal hood . I have to do a bit of work to the front lip to smooth out the spot welds and it will be ready to block sand completely and primer it and it will be ready to make the top mold .

 

[horse sence]

I primered it with high build yesterday .Block sanded it this morning ,starting with 180 ,then 400 then 600 grit .It is as flat and smooth as it can get .Now i need to turn it upside down and sharpen the bottom edge of the edge of the hood ,i will use bondo and sand to a sharp edge ,this will allow me to make a flange so the finished hoods will have a finished edge.The next step will be to wax the top with mold wax ,then spray 3 coats of liquid mold release ,it dries like a sheet of plastic ,then it will be ready to spray on the black tooling gel coat and start fiber glassing .I will start taking pics of each step as i go from here @dennis112 ,I cant wait to see what you have in mind .

 

[horse sence]

I spread bondo on the back side of the hood edge.

I then used my angle grinder to level it down to about 3/16 inch keeping the edge knife sharp .

I then sanded the very edge in a very slight angle until i hit the metal edge from the hood and stopped ,you need this edge in a slight angle so it will pull from the mold, it is almost not noticeable it is so slight .

This is about what you should end up with

Well that was kind of a bad pic.
In about an hour i will wax the top with mold wax ,in the morning i have a little bit of prep work and i will be ready to start on the mold for the top skin.

 

[horse sence]

This is the mold wax .It is pure carnuba wax and not at all like car wax ,it is thicker and very hard to work with .The purpose of the part being waxed is for a release agent between the mold and the underlying part ,or the part inside the mold .There will be a spray on release agent also that i will apply tomorrow .

At least two coats should be applied ,especially with these deep pockets or i may wind up with a big paper weight .You can see the difference in the color and shine right away .Do small areas at a time because it is hard to work with .

Have you ever waxed fiberglass parts before ? It builds up static electricity charge and will send a spark right through your pants .. AHHH ! ZIPPER ZAP!Got two coats on it ,just about broke a finger hooking it in one of those pockets .It is ready for tomorrow ,i hope to start early .I will take pics when i can ,things will get kind of sticky .

 

[Hack]

Very cool! Thanks for taking the time to document your work.

 

[horse sence]

Here we go ! I waxed it last night but i still have a little prep work this morning .I needed to be able to make a flange around the outer side and back end of the mold so i used 2 inch masking tape ,i stretched out about 6 feet and stuck it to a clean smooth table top .I did this 6 times layer on top of layer so it would be stiff .I carefully lifted the tape ,all 6 layers together ,and stuck it to the bottom lip of the hood and pressed it down to make sure it stuck .I wanted it to hang out about 3/4 -1 inch .You will see what this is for when the mold is removed from the hood .

Now it is ready for the liquid mold release .You can spray this from a normal paint gun but it will eventually ruin it so use an old one or a cheapy from Harbor freight ,they work fine .Spray a light coat and allow it to dry ,depending on the out side temp. it will not take long .I sprayed 3 coats allowing it to dry between coats .

Now we have a thin plastic barrier between the gel coat and the hood ,make sure to spray the edges as well or you will not get the hood out of the mold
We are ready for gel coat .I am using black tooling gel coat .

There is a few ways to apply this ,paint brush ,roller ,or spray it on but it requires a gun that will spray very thick materials .I am using a bed liner gun set to spray as fine as possible .

It is gel coated .Two coats wet on wet , making sure all the surface and the masking tape and edge is covered .All that is left now is to wait for it to set up ,and that may take a while today because it is a bit chilly out side .I hope around 12 or 1 oclock i will be able to lay up the first layer of 6 .the first layer will be allowed to harden completely so that may be all i can do for today .

 

[horse sence]

The gel coat set up faster than i was expecting. I have my first sheet of 2oz mat cut and laying on the hood .
Five gallon bucket of ISO resin ,assortment of natural bristle brushes and a roller ,box of rubber gloves because nitril gloves will melt, and i am ready .

Do not try to wet the down the entire thing at once ,you may be in trouble .Do about 1/3 -1/2 at at time ,give your self time to make sure you get all the air out of the first half then wet down the other half .The roller gets out the air faster than trying to do it with a brush ,use the brush to get tight places .The first layer is done ,it will harden until tomorrow when i will add the last 5 layers .Then it will cure for at least a day and i will build the supports .

 

[horse sence]

Got 2 more layers on late last night and finished it early this morning .I Built a box on top of the mold ,it fits up tight to the mold . I cut strips of mat and stapled it to the box and wet it with resin and rolled it down with my roller ,it is only fiberglassed around the perimeter so it would not distort the mold .Now the mold will keep its shape and every hood that comes out will be the same because the metal hood is still inside the mold .I still have a couple of 2x4s to fill in the center of the box so it will set on my cart ,and cut some holes in the side of the box for clamping and i can flip it over and trim the exes material away .Then i can remove the metal hood .

 

[horse sence]

I filled in the center of the box with 2x4s ,cut holes in the box for clamping the under brace in place, after the top is made, and turned it over

.It must weigh about 200 lbs right now .I removed the masking tape ,cut off the exes material hanging over the side and sanded the remaining flange smooth with the bondoed hood edge .

It is time ! Out comes the hood ,it came out so easy i couldn't believe it .

Remember the liquid mold release i sprayed ? Here it is ,it peeled out very easy .

Here is the mold but it is still not ready to use ,i have to block sand with progressive grits of wet paper until i get to 600 grit ,then i have to wax with mold wax and it is ready to use .

The hood came out damage free,i think i will hang it on the wall ,who knows i may make another mold from it
.

Making the under brace and then the mold will be next .