Building a fiberglass hood

Making the mould

Ok started this project this weekend and this is what we have so far

We set the original hood on some tressels and waxed it with 3 coats of carnauba wax before applying the gelcoat. As you can see the 1st half we applied with a brush which was a mistake the 2nd half was done by pouring the gelcoat onto the hood and spreading it about with a plastic scraper.

Once the gel coat hardens up we layed out our first layer of cloth and cut to size, we then removed the cloth and pored resin over the hood spreading with the plastic scraper then layed up the sheet and smoothed it out again with the scrapers before apply a second coat of resin making sure that all the cloth was wet. excess resin was then drawn off leaving a smooth finish.

Next weeken we will lay up the next 2 layers of heavier cloth and the ribs etc to keep the mould in shape

[598TransAm]

Wow....Are you doing this at work or at home?

Originally Posted by 598TransAm

Wow....Are you doing this at work or at home?

I have a barn i rent with some buddies for storage of cars and a workshop, so its being done there.

[Mb125]

Looks good....you must have alot of spare time on your hands

Originally Posted by Mb125

Looks good....you must have alot of spare time on your hands

It hasnt actualy taken long to get this far, The gelcoat takes about 20mins to set up and we did the first coat of resin and cloth before we finished up today. Its probably about 3 hours work so far.

Its being done whilst we finish the rest of the work to do on the car

[Sct402]

Awesome, can't wait to see how it turns out!

[TropicDave]

Years ago, I worked for Precision Boatworks and for Chris-Craft, both in Bradenton, FL. Applied many a layer of fiberglass during that time (mostly with a chopper-sprayer, which - using compressed air - sprayed the resin and catalyst and simultaneously chopped a yarn-sized fiberglass string into itty-bitty pieces onto the mold all at one time) and I can suggest to you that the mold be about 3/8" thick at the least, even with the ribs you'll 'glass into it. This will give the areas not reinforced some stability, and shouldn't add too much to the weight.

Also, you DID use mold release, right????

I keep wanting to do the same with the spoiler on my Can Am, as you just can't get them anywhere...and I know it's been done before (check Jim Hand's V-8 book) but not until I get it refinished and repainted.

Originally Posted by TropicDave

Years ago, I worked for Precision Boatworks and for Chris-Craft, both in Bradenton, FL. Applied many a layer of fiberglass during that time (mostly with a chopper-sprayer, which - using compressed air - sprayed the resin and catalyst and simultaneously chopped a yarn-sized fiberglass string into itty-bitty pieces onto the mold all at one time) and I can suggest to you that the mold be about 3/8" thick at the least, even with the ribs you'll 'glass into it. This will give the areas not reinforced some stability, and shouldn't add too much to the weight.

Also, you DID use mold release, right????

I keep wanting to do the same with the spoiler on my Can Am, as you just can't get them anywhere...and I know it's been done before (check Jim Hand's V-8 book) but not until I get it refinished and repainted.

We have laid up a 300g/m cloth as the first and the 2nd two will be 800g/m cloth so we will have about 1/4" plus the gelcoat.

As for release agent we used 3 coats carnauba wax followed by a spray release and did a test piece first of all to make sure it released

[Poncho1961]

This is interesting, Thanks for postin it.

Is the gel coat real thick, does it flow on its own very much? Did you have to damn up the edges to keep it from slowly flowing off the hood or is it thicker than that with no flow of its own?

Is there a time frame that you have to follow as far as how long to cure the gel coat before applying the cloth or apply it within a given time for best bonding?

Originally Posted by Poncho1961

This is interesting, Thanks for postin it.

Is the gel coat real thick, does it flow on its own very much? Did you have to damn up the edges to keep it from slowly flowing off the hood or is it thicker than that with no flow of its own?

Is there a time frame that you have to follow as far as how long to cure the gel coat before applying the cloth or apply it within a given time for best bonding?

This is the first time i have messed with fiberglass so its a learning experience.

The gelcoat is very thick, we tried to brush it on at first but decided when we did the second half of the hood that we would pour and smooth it out with a scraper.

We deliberatly let it run over all the edges so that we will have a edge to lay the glass cloth up on when we use it as a mould. The gelcoat pretty much stays where you put it

We let the gelcoat harden up to a point where it was slightly tacky before applying the first sheet of glass cloth

[Poncho1961]

Is that the gel coat in the last pic that looks like plastic hanging from the shaker hole and off the sides of the hood?

Originally Posted by Poncho1961

Is that the gel coat in the last pic that looks like plastic hanging from the shaker hole and off the sides of the hood?

The last picture is the gelcoat with a single layer of glass fiber cloth. We are using the proper woven cloth not the chopped strand type

Picture 7 shows the gell coat, as you can see it doesnt really come past the edg of the hood we just brushed some along the edges to make sure that when we added the resin and cloth it couldnt seap under the gelcoat

[TropicDave]

Originally Posted by 55 Starchief

We have laid up a 300g/m cloth as the first and the 2nd two will be 800g/m cloth so we will have about 1/4" plus the gelcoat.

As for release agent we used 3 coats carnauba wax followed by a spray release and did a test piece first of all to make sure it released

Sounds good. It's important to get the rigidity since even the mold can flex and split...

Usually we sprayed the gelcoat, but I don't see where brushing it on wouldn't work. Your contact surface is against the mold, and as long as your mold is clean and smooth (you'll want to sand and wax it, just like on a paint job...we kept at it until there was damn near a mirror finish, but that was how my boss at Precision was...) there shouldn't be too many problems.

Originally Posted by TropicDave

Sounds good. It's important to get the rigidity since even the mold can flex and split...

Usually we sprayed the gelcoat, but I don't see where brushing it on wouldn't work. Your contact surface is against the mold, and as long as your mold is clean and smooth (you'll want to sand and wax it, just like on a paint job...we kept at it until there was damn near a mirror finish, but that was how my boss at Precision was...) there shouldn't be too many problems.

I had read you can spray the gelcoat but im not sure what you would need to do it, i only have a tiny compresor and a cheap gun.

This was an exercise to see if it was possible to make a hood as shipping a fiberglass unit to the UK costs 3 times the price of the hood. If it works we will try and take moulds of other panels on the car

I was woundering why you were making the Hood. I didn't think about shipping.