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RE-TurboFB 12-20-10 01:02 PM

Trying to make myself a fiberglass hood.
 
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Hey guys,
So I'm still trying to make a liteweight fiberglass hood for my FB. This is my 2nd try and im still not happy with it. close but not there yet. This one weights in at 13.8 lbs. wich is about 65% lighter then stock. i used a white gel coat and isophthalic tooling resin so its pretty strong.

I think I went wrong when I fiberglassed the frame to the skin. I think a panal bonding epoxi might be a better option.

Anyways tell me what you guys think..

bshusted 12-20-10 01:38 PM

If you want to continue perfecting your method, I'll take this reject off your hands.

stofficer1226 12-20-10 02:46 PM

Would you mind to post up a half way DIY. I have been trying to figure out how to do as many body panels as much as possible. I am trying to find info on anyone who might have done a Lexan rear glass on the hatch. I don't know if the front wind screen is suitable for a street driven car. (being scratched)
Would fiberglass fenders be worth the trouble?

13x 12-20-10 03:11 PM

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wow ... keep us updated ... I will soon be embarking on attempting to make a fiberglass version of this one as it does help with engine temps in Vegas but weight reduction would be a plus, it's sad the vendors do not see a viable market in the first gens ;(

Attachment 715900

Brigdh 12-20-10 04:04 PM

Nthing a writeup, please

RE-TurboFB 12-20-10 06:59 PM

Yeah I can do a step by step wright up on how to make a fiberglass hood or anything for that matter.. I can do a half assed one later or I can do a detailed one when I do my next hood.

As of right now my front air dam, splitter, front fenders, cowl panel, Rear wrap and hood are fiberglass.
fiberglass door skins are next on my list once I get the rest of the fiberglass up to par.

Thanks for the replies guys!

13x 12-20-10 07:37 PM

wow how much weight you figure you shaved off so far?

RE-TurboFB 12-20-10 08:10 PM

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Before you can make a fiberglass hood, You need a mold. To make a mold the first thing you will need is a plug. The plug is the part you are making the mold from.
I used a stock hood as my plug. There where a few chips and scratches so I did some sanding to make sure the whole thing was good and smooth.

After it's good and smooth, clean it with a prep solvent or soap and water. when its dry, put like 5 layers of 100% pure carnauba wax on.

RE-TurboFB 12-20-10 08:11 PM

My scale says the stock hood is close to 39 lbs, And says the fiberglass one is 13.8 Lbs. But i do not know how accurate it is.

As for the whole car I dont how much weight i have shaved off of it yet. i have done a few thing to get it lighter. like remove the the tar from the interior and put in a fiberglass dash. I would have to put it on a scall to find out how much weight i have shaved off it.

RE-TurboFB 12-20-10 09:43 PM

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After the waxing you need to spray the waxed plug with PVA. I use a Partall # 10 PVA. They say to use a HVLP spary gun with about 10PSI at the cap. Spray the plug with light mist coats cuz the pva does not like to stick to the waxed surface. apply as many coats it takes to turn the plug a light green.

After the PVA has dryed. you can apply the gel coat I use a gel coat gun and spray it on to the plug, But you can also use a paint brush. as soon as the gelcoat gels you can mix up some resin. I like to use a isophthalic tooling resin. paint the resin over the gel coat with a paint brush then I use a couple layers of 1.5 OZ chopped strand fiberglass mat. Then paint on more resin untill all the mat has been wetted out.

RE-TurboFB 12-20-10 10:10 PM

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After the resin has cured you can pop it off the plug. use a plastic wedge to pop the edges off the plug and the rest will follow.

A little bit of trimming and then you have a fiberglass mold

The PVA should just peel off in a layer or warm water will melt it off.

2GSLSE 12-21-10 03:24 AM

Looks good but you forgot a TII scoop

82transam 12-21-10 08:27 AM

Looking very good! Good writeup so far too. Like a bunch of others I've been wanting to do some fiberglass work for my FB. maybe this will get me in gear ;)

dream36realms 12-21-10 09:18 AM

have you thought about using bar stock as bracing? That is what I been thinking aboutt for when I embark on mine.

stofficer1226 12-21-10 09:38 AM

What is your weight goal? Idealy I'd like to see my FB at 1,800lbs with stock dash, center con, carpet, headliner. Realisticly, I don't think that's possible.

Directfreak 12-21-10 10:07 AM

Very Nice work on the Dash!!

https://www.rx7club.com/attachment.p...7&d=1292904587

Perhaps you can emulate this REALLY GOOD IDEA from Australia.

It's a great place to put aftermarket gauges, without screwing up
the stock look of your dash. Check it out!

http://www.ausrotary.com/download/file.php?id=23110

Directfreak 12-21-10 10:28 AM

Also, I wish you closer to me. I actually have a mold for the TII hood scoop for the FB. I bought it years ago. I have the top skin mold, not the bottom reinforcement mold. I would give it away in exchange for two hoods.

https://www.rx7club.com/picture.php?...ictureid=26739

dream36realms 12-21-10 12:08 PM

OMG, I so want that hood. You gotta do a run or sell it :( I'd make you a free or two hoods ;)

KansasCityREPU 12-21-10 12:45 PM


Originally Posted by Directfreak (Post 10377496)
Also, I wish you closer to me. I actually have a mold for the TII hood scoop for the FB. I bought it years ago. I have the top skin mold, not the bottom reinforcement mold. I would give it away in exchange for two hoods.

https://www.rx7club.com/picture.php?...ictureid=26739

If you make this hood at a resonable price, you will have orders stacked up. I want one.

RE-TurboFB 12-21-10 02:39 PM


Originally Posted by KansasCityREPU (Post 10377745)
If you make this hood at a resonable price, you will have orders stacked up. I want one.

As of right now I cant really make any good money off of fiberglass FB parts.. That and I cant sell them through the forum unless I sign up to be a vendor. I dont have the money to pay vendor dues and I dont want to get in trouble with the forum.

Man_in_black49464 12-21-10 03:16 PM

if there were no risks in making money we would all be rich, but i feel your point.
you wouldnt need to be a vendor really you should just make a few at a time and sell them just make sure you follow through!!!! and we will make sure your work is paid for.

And if the rx7 club nazi says you cant sell it on here then contact the people who want you to make it like me and ill spread the word and so will the other guys your doing us a favor with your skills and we would love to see the product!

13x 12-21-10 03:29 PM

there would be a lot of interest, build it and they will come

jgrewe 12-21-10 05:02 PM

If you want to save weight skip the whole under frame. Just use the parts that you need to hold the hinges and latch, maybe just the perimeter. You can gain strength across the hood with a 4mm foam core or even some 3/4 PVC pipe that is ripped in half and used as a spacer to build channels out of fglass.

I bet you can get it under 10lbs with no problem.

RE-TurboFB 12-21-10 08:30 PM

yeah I have been thinking about changing up the frame design to save weight.. My only fear is that the hood might be to flimsy.

I'm going to try some new ideas on the third hood. I'll do a detailed write up on the next one with lots of pictures. As soon as I get some cash for supplies.

stofficer1226 12-22-10 11:49 AM

from start to finish how much does a hood cost you in materials? I've done small fiberglass repair jobs but nothing to this extent. What kind of price range am I looking at?

jgrewe 12-22-10 12:01 PM

Materials are cheap, time is the most expensive part. Hood itself, probably $35-50 depending on resin used.

My FC hoods use a foam core for most of the underside. I've played around with different ways to make raised areas to add strength. I've finally just doubled and tripled up with strips of the foam core in certain areas that would tend to lift from underhood pressure above 130mph. Those hoods weigh about 11-13 lbs and there is a lot of extra sqft compared to an FB.

The biggest trick with the foam is to taper the edges so they don't hold air during lay up.

MountainScreamer 12-22-10 12:14 PM

Jgrewe, could you post a picture of the underside?
What kind of foam are you using?

nofords 12-22-10 12:27 PM


Originally Posted by RE-TurboFB (Post 10378481)
yeah I have been thinking about changing up the frame design to save weight.. My only fear is that the hood might be to flimsy.

I'm going to try some new ideas on the third hood. I'll do a detailed write up on the next one with lots of pictures. As soon as I get some cash for supplies.

My race car just has a perimeter of 1/4"sq. aluminum stock and hood pins and it holds up well at 140+mph down the track. I do not have any issues with it.

I would suggest disposing of the steel back and replacing it with something similar with bonded aluminum box channel for mounts and prop rod holes.

The only issue I have with mine is that the hood tends to be really flimsy in high winds while up working in the pits. if the wind comes from the rear of the car it tends to wobble around. Not so much from the front. I solved this issue by running double prop rods. you will notice that the car has provisions for one each side. Just bend a second prop rod mount tab from a 'J' to an 'L' and insert! :nod:

RE-TurboFB 12-22-10 02:24 PM


Originally Posted by nofords (Post 10379443)
I would suggest disposing of the steel back and replacing it with something similar with bonded aluminum box channel for mounts and prop rod holes.

The hoods I made use a fiberglass backing.

RE-TurboFB 12-22-10 02:38 PM

Resin: $36.50 a gallon
gelcoat: $41.95 a gallon
1.5 oz CSM fiberglass: $3.40 for a 50" x 1 yard peice
PVA # 10: $15.95 a gallon
wax: $10.95 for 16 oz's

prices just to get you guys a idea of what this stuff costs.. plus shipping costs me out the ass!

I'm guessing it costs me around $110 to make one PLUS all my time.
I'll keep track of what I use on the next one and find out what they really cost.

jgrewe 12-22-10 06:34 PM

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Here is a shot of an FC hood.

Not to bust your balls RE but your time is worth good money but you only need about a quart of gelcoat(being wasteful) and 3 quarts of resin at the most. A gal of PVA is almost a lifetime supply and a tin of wax will last a loonnnnnggg time too.

The money is from all the prep time from mold making all the way to the trimming of the new part. Guys, if you haven't tried this stuff, I'll tell you its time consuming to do it right. A lot of times you won't know if you screwed up somewhere along the line until you pull the part out of the mold !

Where do you buy from? I have a great place in town that I know ships all over check out fgci.com (Fiberglass Coatings)

RE-TurboFB 12-22-10 07:42 PM


Originally Posted by jgrewe (Post 10380008)
Here is a shot of an FC hood.

Not to bust your balls RE but your time is worth good money but you only need about a quart of gelcoat(being wasteful) and 3 quarts of resin at the most. A gal of PVA is almost a lifetime supply and a tin of wax will last a loonnnnnggg time too.

The money is from all the prep time from mold making all the way to the trimming of the new part. Guys, if you haven't tried this stuff, I'll tell you its time consuming to do it right. A lot of times you won't know if you screwed up somewhere along the line until you pull the part out of the mold !

Where do you buy from? I have a great place in town that I know ships all over check out fgci.com (Fiberglass Coatings)

Yeah those prices where just to show you guys how much I pay for supplies..

I'm still on my first tin of wax. your right a gallon of PVA does last a long time.. I have had too learn how to do this stuff all by myself.. So there was a lot of trial and error( lots of wasted supplies) trying to figure out how to use the stuff.

I use around 24 OZ of gelcoat on a hood, and around 96 OZ of resin on a hood. I know I could be using less meterials since my hood does weigh 13.8 Lbs.

I get my supplies from UScomposites. They are on the east side and I'm on the west so I pay big time on shipping.

I have always wanted to talk to someone that does this kind of stuff. To find out how they do it, where they get there supplies etc....

Thanks for the info!

jgrewe 12-22-10 08:26 PM

The guy that taught me a lot had a company that built boats. That alone saved me a lot of time and money because he would tell me the problem I was on my way to having before it happened:icon_tup:

There was a lot of, "you might want to wait a little more..." and "I would get on that about now"

I've been thinking about trying some of the UV cured resins but I can only find them in Cali. They have a long shelf life and can be cured with lamps or just putting the part out in the sun for a few minutes. Best thing is they don't stink from the styrene.

Jhereg 12-22-10 08:36 PM

Work looks awesome, If I didn't already have a used mariah hood sitting to the side right now I'd really be interested in one. Maybe a fiberglass one using mariah style scoops? That would be really nice.

RE-TurboFB 12-22-10 09:45 PM

WOW! Thanks jgrewe! That site is awesome! So many options... Damn I wish I could find a supplier in the west side of the US..

It must be great to be able to just pick that stuff up from the store..

elmerxfudd 12-23-10 06:00 PM

this thread rocks, looking forward to the how too.

vmarx7@yahoo.com 12-24-10 07:53 AM


Originally Posted by Man_in_black49464 (Post 10377999)
And if the rx7 club nazi says you cant sell it on here then contact the people who want you to make it like me and ill spread the word and so will the other guys your doing us a favor with your skills and we would love to see the product!

add me to the list of contacts if/when produced
interested in the dash w/ 3 gauge pods & the t2 hood

RE-TurboFB 12-24-10 04:30 PM

Hey guys,
Thanks for all the good comments!
I make a living on fiberglass boat repair. So I never really plan on making and selling fiberglass for the FB as of right now. But if it would be doing you guys a favor I could make a couple more.. as long as the forum permits it.

I would let this one go out of my "privite stash" if anybody wants it.. PM me with a offer or to add yourself as a contact if I make some later. (as long as it's cool with the forum)

I will make a detailed write up with lots of pictures as soon as I make my next prototype hood.

Thanks guys! and thank you rx7club!

stofficer1226 04-27-11 11:34 PM

Any updates???


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