Repairing and painting the fan shroud

[tirwin]

I have the fan shroud off the car and want to do a little clean up. The shroud has been scraped and the color is fading. The fiberglass has a lot of micro cracks in the surface. There is a good crack near the opening for the intake runner at cylinder #6.

I've got zero experience with fiberglass. I read a generic article that talked about repairing fiberglass and it suggested using body filler. What's the Pelican brain trust say? Not sure how to align the big crack before using the filler.

Now painting. I've read that VHT makes an engine enamel in a rattle can that can take high heat. Supposedly the Chevy engine block color is a pretty close match.

Whaddya think? Anyone see any problems with this approach or have any other suggestions?

[moneymanager]

A search here will turn up a bunch of lore on this question.

[E Sully]

Heres a thread.
Fiberglass Engine Shroud - Best way to refurbish?

[tirwin]

Thanks. I have read a bunch of threads (had an easier time using the Google search method). I have seen a lot of different suggestions but I didn't see too many that showed repairing methods.

Here's what I'm going to try:

- pressure wash it
- epoxy the crack
- sand with 80 grit
- clean with denatured alcohol
- filler
- final sand with 300 grit
- paint with Duplicolor engine enamel

[Discseven]

Originally Posted by tirwin

I have the fan shroud off the car and want to do a little clean up. The shroud has been scraped and the color is fading. The fiberglass has a lot of micro cracks in the surface. There is a good crack near the opening for the intake runner at cylinder #6.

I've got zero experience with fiberglass. I read a generic article that talked about repairing fiberglass and it suggested using body filler. What's the Pelican brain trust say? Not sure how to align the big crack before using the filler.

Now painting. I've read that VHT makes an engine enamel in a rattle can that can take high heat. Supposedly the Chevy engine block color is a pretty close match.

Whaddya think? Anyone see any problems with this approach or have any other suggestions?

Hey Tim... how about shooting & posting some sequence pics.

[moneymanager]

Many sites selling fiberglass products have a "how to" manual attached. I don't know what kind of filler you are thinking of, but lots of us would just use fiberglass resin. Add a bit of fiberglass cloth to deal with/strengthen/fill in a big hole or tear. All purchasable at your flap store.

[tirwin]

Karl,

Ask and ye shall receive!

I pressure washed it today using a low pressure setting. Just blasted the caked grime off. Then I used this Super Power degreaser that comes in a purple spray bottle at the local FLAPS.



Finish is kinda dull. Not too bad from a few feet away. Here is a close up that shows the general condition all over. You can see that there is still some grime between the texture of the fibers. In some places it almost looks like the surface is cracked. Not split, but kind of like spider webbing.



There are some scuffs on the top that will not rub out.



And here is the crack at the intake runner.



The next step is to try lacquer thinner and/or denatured alcohol to see if I can clean it some more.

[tirwin]

I bought his at the local FLAPS today. I looked at some fiberglass gel stuff at the store and it says to finish with lightweight filler.



Seems like the only place that would need the fiberglass would be the crack. Do you think I could just use some epoxy there? Like I said I have zero experience with fiberglass.

[Bill Jennings]

Hi Tim,

I think using just epoxy will crack again as there will be no strength at the repair.

I would grind the backside a little thinner then use resin and some fine fibreglass mat on the underside to bridge the crack.

This would make a long lasting repair and you can use a little bondo on the top side or fill then sand with resin there.

You can buy small fibreglass repair kits in a box that should have instructions.

Cleanliness is key for good adhesion!

Cheers
Bill

[Bill Jennings]

Whoops Duplicate Post!

[NY65912]

Krylon make a paint for fiberglass in "Sundried Tomato" which is virtually a perfect match for the original red.

[tirwin]

NY,

I wonder how the fiberglass paint holds up in heat? I had seen others recommend this engine enamel because of the heat factor. This stuff has ceramic in it and it takes a few heat/cool cycles to fully cure. I've got to look for some fiberglass repair today so I'll look for the Krylon while I'm out.

[NY65912]

I used it on my 3.8, which got pretty hot. It never did discolor.

[al lkosmal]

here's a few links for you.

regards,
al

Engine shroud refurbishing

engine shroud treatment?

Behold!..........my

[tirwin]

Originally Posted by NY65912

I used it on my 3.8, which got pretty hot. It never did discolor.

Mike,

That's one beautiful engine bay! I have been tempted to change pistons and go to an EFI setup just so I can have a clean engine bay like that.

[tirwin]

Thanks, Al! Beautiful work!

[Discseven]

Originally Posted by tirwin

Karl,

Ask and ye shall receive!

Way to go Tim! It's great to see the parts you're dealing with... the products used... progress... etc.

[NY65912]

Originally Posted by tirwin

mike,

that's one beautiful engine bay! I have been tempted to change pistons and go to an efi setup just so i can have a clean engine bay like that. :d

beware of the slippery slope!

[Ferrino]

I recently repainted my shroud and needed to fill in some holes and repair a couple of small cracks - I used JB weld and it worked very well. Guess it depends on the extent of the crack. I also used Duplicolor engine enamel.

[porschetub]

I personally wouldn't use epoxy,the shroud was made in polyester and thats best to repair with,vee the crack out from the underside with course sandpaper ,make sure you feather the edges towards the crack to almost nothing.
Support the cracked area and tape over it from the top (gelcoat surface) ,get chopped strand mat (csm)and cut or tear it into small sections,wet the sanded area with the polyester resin and laminate your mat out from the centre of the crack till its back to original thickness + , allow to dry overnight .
Remove your tape and if you have done it right you will have a good finish with little sanding required,the under side after sanding to shape and thickness will only then require a cost of resin brushed over it to seal the fibers.
Key points are ;
Old fiberglass must be clean,no grease or oil,
repair area's must must be sanded well for a good bond,
don't use too much hardener ,it weakens the repair ,1-2% is best in a warmish area, also too much hardener reducing your working time,
don't use too much resin,just enough is stronger,
only use polyester repair resin as it has wax in it the seal the surface so you can sand it,
pick a nice day out of the sun or preheat your working area,
use rubber cloves to stop this sticky cr#p getting on you ,epoxy is worse and bad for your heath.
avoid getting the hardener on your skin ,very nasty stuff.

You will need,
60-80 grit sandpaper,
buy a small polyester repair kit from a hardware shop,they usually come with the csm (fiberglass matt)
a few throw- away brushes,
small bottle of acetone to pre- clean repairs and your hands/clothes/dog etc etc
roll of painters masking tape,
some mixing sticks (i use wooden chopsticks)

Good luck