Engine Shroud Refurbishment, There's a hole in my boat Options

[DennisV]

Does anyone have first-hand experience refurbishing their engine shroud that they can share? Best practices? Lessons learned?

I bought the best (err only) original engine shroud that I could find that I think is correct for our engine. Thanks for the guidance on that. It might work as is, but it could sure use some help. Faded. Cracks. Etc.

I've done some searching, but the best resources I've found so far are boat repair videos.

[porschetub]

Does anyone have first-hand experience refurbishing their engine shroud that they can share? Best practices? Lessons learned?

I bought the best (err only) original engine shroud that I could find that I think is correct for our engine. Thanks for the guidance on that. It might work as is, but it could sure use some help. Faded. Cracks. Etc.

I've done some searching, but the best resources I've found so far are boat repair videos.

Ok having worked in most types of fiberglass for a fair while I suggest remove the broken cooler duct and repair it first,grind out the hole from the inside and remove all the fractured area's with a grinder,clean the part as much as possible then apply several layers of painters tape on the outside to get the shape back for your repair.
Them mix up polyester resin and apply to the inside with chopped strand matt layed into it,just a few layers to hold the shape,you can build it up later to get the original thickness,when thats done remove the tape and apply a thin layer of filler to correct the shape.
Leave the part off for the meanwhile as it makes the rest of the shroud repair and painting easier,apply the same process of repair to that part in area's that are damaged.
It is very important to clean these area's as oil can be present on these parts and will effect the quality of the repair and final painting.
I used acrylic enamel on my shroud and it has lasted well and provides a shine similar to the original gelcoat that was used when this part was molded.
You will need the following ;
small tin of 1k paint thinner/reducer for cleaning,
a small fiberglass boat repair kit with will usually include some chopped strand matt,the GP resin and hardener (MEKP) ,will be in that kit,
a small tin of acetone for cleaning parts ,brushes,hands etc,
drylube sand paper ,80 grit,220 ,320 the 400 for final sanding before primer,
1 x colour matched grey spray can for cooler ducting ,
1 x black spray can,
1 x spray can of Ik primer,
masking tape,
small tin of lightweight polyester filler,
pop-rivets and backing washers to refit ducting after painting,
throw away cloves and other consumables.
Make sure your working temp is suitable and the humidity is low,resin is generally 1-2 % dependent on temperature,take your time and you will get good results,mine came out really nice,good luck Dennis.

[DennisV]

Ok having worked in most types of fiberglass for a fair while I suggest remove the broken cooler duct and repair it first,grind out the hole from the inside and remove all the fractured area's with a grinder,clean the part as much as possible then apply several layers of painters tape on the outside to get the shape back for your repair.

Thank you for this detailed post. It is really helpful. A couple follow up questions:

Is it normal to be able to see the fibers so prominently, or is this indicative of the material eroding?


I have never tried to rivet fiberglass before. Will I have trouble getting a tight fit without damaging it? It has been a long time time I had to rivet anything, but I seem to recall it wants to sandwich the material quite firmly before snapping off.

Why did you choose to paint rather than take the original gelcoat approach?

Thanks again.

[porschetub]

Ok having worked in most types of fiberglass for a fair while I suggest remove the broken cooler duct and repair it first,grind out the hole from the inside and remove all the fractured area's with a grinder,clean the part as much as possible then apply several layers of painters tape on the outside to get the shape back for your repair.

Thank you for this detailed post. It is really helpful. A couple follow up questions:

Is it normal to be able to see the fibers so prominently, or is this indicative of the material eroding?


I have never tried to rivet fiberglass before. Will I have trouble getting a tight fit without damaging it? It has been a long time time I had to rivet anything, but I seem to recall it wants to sandwich the material quite firmly before snapping off.

Why did you choose to paint rather than take the original gelcoat approach?

Thanks again.

The fibres show up because the gelcoat has failed,mine had a few area's like this and,thats common as they are old and this area is subject to heat,the black ones are generally the worst.
Gelcoat repair is still possible but it would be expensive and gelcoat is difficult to spray when thinned as it is designed to be sprayed into a mold to achieve a nice shine.
My choice of paint was only because I had some I wanted to use up,you could improve things by using a 2k black spray can but not sure of it in this application.
The factory used pop-rivets so you should be fine,you could still leave the duct on but that will make repair more difficult just depends on if you can get to the damaged area to grind it out,maybe you could show a pic of the underside ..that would help.
Cheers.

[DennisV]

Gelcoat repair is still possible but it would be expensive and gelcoat is difficult to spray when thinned as it is designed to be sprayed into a mold to achieve a nice shine.

This is good to know.

maybe you could show a pic of the underside ..that would help.

This is it after 2+ hours of degreasing. I knew this was going to take some effort, but it's turning into a real project. It's got several major cracks and some holes.

Thanks everyone for sharing their experience. I never imagined I'd be learning about fiberglass to work on a Porsche. (IMG:style_emoticons/default/wacko.gif)