Fiberglassing how-to instructions?

[JohnJL]

I want to make up a cockpit vent from the top of the hood vent through to the central vent on the dash and out into a hose pointed at the driver (sorry co-driver!)

I'd like to try my hand at fiberglassing up a piece or pieces but I dont want to do a mold. I've seen good videos on youtube how to molded pieces, any suggested writeups on what material (balsa? plastic? sheet alu?) to use as a substructure and how to get a good result?

thanks

[Cory M]

decent write up here, info is for carbon fiber but fiberglass is same process:

http://forums.corral.net/forums/showthread.php?t=660756&page=1&pp=35

[Ed Bighi]

I've wanted to make the same thing. Don't forget to make a provision for draining water. This is the one thing, that surprisingly, only Smart Racing has made. Why waste such a well placed intake. There is a massive ammount of air pressure there. Worked for the 956/962 as well. I have had the clock hole deal from Smart Racing. Neat, very effective, enough to kill you in the winter, but, if you have a boost gauge in the clock hole? I guess you could dump that hose right to the center vent if you want. Hey, do that.

Also, since we are on the subject, there is a solution for the defrosters in a fully stripped car without heat that few people know about. If a 911 is moving faster than 30 mph, has the heat exchanger ducting disconnected, there is enough flow into rocker heater pipes to provide just enough airflow to defog a windshield. Works even better with a windshield treated with shampoo for anti fog. Especially if the flapper boxes are removed. In fact, I recommend removing them for a car without heat exchangers. Remove them before they are even more stuck. Even better with one window cracked. At higher speeds the rear roof air vents do the job of air evacuation just as well as a cracked window. And that incoming air is still a little warmer than ambient due to the hot exhaust. Just enough. Just connect the oulets at the foot area directly up to the defroster outlets with hose. Works amazing. All because of the aerodynamics in a 911. No need to have exchangers connected. Unless you want heat for comfort. But for pure defrosting, no exhangers are needed. Just open inlets around that transmission area and the least impediment possible past the oulet at the footwell.

[wowzer911]

what ever you use for a mold is a matter of choice, you can use cardboard if you like, but remember you need to treat it with a release agent or use non-stick material to keep the resin from adhereing to the mold, unless you're going to fiberglass over it permanently.

[JohnJL]

Thanks guys.

I'm trying to do it in one piece, without a mold. as in, over thin alu sheet.

My clock hole is full of a 6-cylinder head sensor gauge.

Interesting on the defrosting note. I have no exchangers and no ducting, but I do have 2 12v hairdryers hooked up to the front ducts.

[slodave]

Originally Posted by Cory M

decent write up here, info is for carbon fiber but fiberglass is same process:

http://forums.corral.net/forums/showthread.php?t=660756&page=1&pp=35

Thanks for the thread! I was reading it before I went out tonight. I might have to go back and read the rest...

[Kroggers]

Originally Posted by JohnJL

Interesting on the defrosting note. I have no exchangers and no ducting, but I do have 2 12v hairdryers hooked up to the front ducts.

Could you post some pictures and details on this please, as I am looking for a solution like this

[JohnJL]

Sure thing Paul. I'm at work now but its pretty straightforward. List of ingredients;

1. 2x 12v hairdryers with cigarette lighter plugs from a camping/RV store
2. 1 fused (20 amp) relay
3. On/off switch
4. Race tape
5. 1 meter 10 gauge power cable.

The hairdryers fit snugly into the existing defrost vents behind the dash. Jam 'em in there good and secure with race tape. I prefer red as it matches my paint.

Clip the cigarette lighter adapters off the dryers and connect the power +v cables from both dryers to the relay (87 from memory?) The +v cable is the one connected to the center terminal on the lighter adapter. Connect the ground of each to a ring terminal and attach to the chassis. Connect 85 on the relay to the chassis also and 86 to a switch on your dash. 30 on the relay gets power directly from your battery or fuse panel. Connect the other terminal on your switch to +12v. Turn the switches on both dryers on (and tape them on for good.)

Done!

[JohnJL]

Cool site above though not what I was looking for...more of a step-by-step for making glass parts without molds.

Funny how he compains that 4lb doors are "too heavy!"

[9elf]

cheap demisters here

http://shop.ebay.com.au/items/__car-demister_W0QQLHQ5fAvailToZ15QQ_armZ1QQ_armmZ63QQ_f romfsbZQQ_ruuZhttpQ3aQ2fQ2fshopQ2eebayQ2ecomQ2eauQ 2fitemsQ2fQ5fQ5fcarQ2ddemisterQ5fW0Q51Q51Q5farrQ5A 1Q51Q51Q5ffromfsbQ5AQ51Q51Q5ftrksidQ5Am270Q512el13 13QQ_trksidZm270Q2el1313

[FenderBender]

I do not know if this will help? Page three he shows how to use a tee shirt for making a mold.
Another IROC build - Aussie RHD 3.8

I have seen felt used for custom speaker enclosers. Shape it how you want cover with fiberglass resin and fiberglass if you need it for strength, let it harden, then do the trim work.

If you come up with something that works please post pictures and share it with us.

[moneymanager]

How beautiful do you want it? That may not be relevant for anyone defrosting his 911's windshield with hairdryers but...
Here are a couple pics of an oil cooler duct which may give you some ideas.

[Zeke]

You can sculpt a foam form of what you want and glass over it. Then dissolve or otherwise remove the foam core. If you can find some packing material like a coffee cup, it won't form too easily, but it sure will dissolve quickly with lacquer thinner. You just have to wait a few days to make sure your glass is plenty cured. Heat helps. Low heat.

[moneymanager]

A little waxed paper over cardboard does ok for a low visibility item like this too.

[JohnJL]

Hhahahaha...hairdryers, very good JH. Thanks for the ideas too. ps. the hairdryers are hidden!


Ahhh...thats the bit I was missing...waxed paper. I thought of forming something out of those blocks of florist foam or foam packing blocks but thought the resin/catalyst would just eat it away.

I just ran out to the craft store and bought 10kgs of air-dry clay. I thought I'd make two molds and make 2 symmetrical parts each.

I cant find any "release agent" at the craft or hardware stores...what do you guys suggest coating the hardened clay with? I saw one store had liquid latex in the "casting" department. It was expensive though...

Can silicon spray be used as a release agent when using polyesther resin?

I'll try my hand at making the mold tonight.

Thanks guys!

[Dcam49]

John,
Florists foam will work, easy to shape too. Instead of using polyester resin try epoxy, it won't attack foam, and it has a lot less odor and fumes. You're in Sydney Australia, that's the capitol of the sailing world and where some of the greatest racing yachts have been built. You should be able to go down to one of the boat yards and they could set you up with everything you need, from the foam, epoxy resin, and different weights of glass cloth too.

[Kroggers]

Originally Posted by JohnJL

Sure thing Paul. I'm at work now but its pretty straightforward. List of ingredients;

1. 2x 12v hairdryers with cigarette lighter plugs from a camping/RV store
2. 1 fused (20 amp) relay
3. On/off switch
4. Race tape
5. 1 meter 10 gauge power cable.

The hairdryers fit snugly into the existing defrost vents behind the dash. Jam 'em in there good and secure with race tape. I prefer red as it matches my paint.

Clip the cigarette lighter adapters off the dryers and connect the power +v cables from both dryers to the relay (87 from memory?) The +v cable is the one connected to the center terminal on the lighter adapter. Connect the ground of each to a ring terminal and attach to the chassis. Connect 85 on the relay to the chassis also and 86 to a switch on your dash. 30 on the relay gets power directly from your battery or fuse panel. Connect the other terminal on your switch to +12v. Turn the switches on both dryers on (and tape them on for good.)

Done!

Thank you John. I will have to try this one out on my car...

BTW, I have the part you are trying to make from SmartRacing installed in my car. Let me know if you need any pictures or measurements. Also, do a search here for Ove. He made his own version from a strip of angled aluminium which turned out really good.

[kidrock]

I've worked with a lot of fibreglass over the years. I think making forms and templates are pretty straightforward. For the inexperienced, the most difficult part will be formulating the correct ratio of catalyst (hardener) to resin. Too little, and the resin won't cure properly...leaving you with a sticky, gooey mess. Too much catalyst, and you'll set all your hard work on fire. Be careful...

[Ove]

Hi John,

Not quite what you're asking for, but I have made an aluminum air intake.



Here's the thread on this: Home made lightweight vent.air intake

And the rest of my vent system: Vent System and Heater - Deleting What I Don't Need, Keeping the Defrost

[JohnJL]

Thanks Ove, I just saw that with Paul's direction. How is the flow from that?

I am just in the middle of the living room watching Top Gear and surrounded by thousands of little styrofoam pellets coming off the cuts...