TECH: Custom fit fan shroud.

Well, the temperature was rising when I sat at traffic lights, so it was suggested that I put a fan shroud on it... I tried making one out of cookie sheets, abut it was too flimsy... So I used a technique I saw on the TV show "Unique Whips" to make subwoofer boxes... Sometimes mindless TV isn't always a waste of time.

The technique involves stretching cloth over a form, soaking it with Polyester (fiberglass) resin, reinforcing it with a little 'glass mat.

Make forms from the diameter of the fan (18") and then gave it 3/4" more (19.5" diameter), then the core area of the fan (17.5 x 18"), plus and extra 1-1/2" on each side, you'll see why in a few.

Notice the the fan area is not centered top to bottom, you have to measure where the center of your fan is when you put the masonite against the radiator core... the masoniste on the radiator chould have centerlines drawn on it and a ruller between it and the center of your fan will tell you edactly how far up of down from the centerline you need to mark it. I drilled a hole in the radiator piece at that spot, put some threaded rod through, and then made the spacers from there.


The engine angle was accounted for with the spacers...


Then I got some of this FABULOUS polka dot t-shirt material that had Lycra in it so it stretched... $3 a yard on the remnant rack at Joanne's... the lady there said I wasn't the first guy to come and and look for cheap material...


I used some staples at first, first in the center, then radiating towards the corners, making sure the material had no wrinkles of not-so-tight areas... You don't want the cloth loose, the resin's weight may make it sag in ways you don't like.

Then I hot glued it down as smooth as I could, so when I put the resin on, it would lay flatter.


Here it is all pretty, ready to be splooged with resin... as you can see it has some nice compound curves, hopefully making the air flow... flow


Wait to post.... I have 10 more pics

 

Here is the first coat of resin, took about 8 oz. on the first pass, then another 8 oz. before I started the matt layer.


I cut the matt into 2: x 4: strips and went around the lip area, pretty good, then filled in the areas around the edge, I just went to the edge because it'll be trimmed off anyway.


I waited 2 days just to be sure the resin was cured, and I cut away some of the material (you are gonna want to do this trust me) and drilled a hole to get a jig saw in... then I used the shittiest jig saw ever made (HF) and cut out the fan hole.


I was starting to get a nice calm Zen feeling about now... I don't know why....


Then I went on the back side and knocked down the areas and wrinkled cloth that got resin on them, and kind ground ot almost flat with a sander. I planned on using my table saw to cut the center from the radiator side, so I wanted it to lay flat.


Last 5 on the way...

 

Got it mostly knocked down and trimmed off the cloth that was still kinda not soaked with resin.


Then I cut the center out leaving the last 1-1/2" I made it wider than the radiator core, so I could mount some aluminum angle... this will keep it rigid, and give me something to screw the shroud to...


When I cut the thing in half!!

The aluminum angle will stay in one piece, and the two pieces will be held together with it. and the angle will be attached to the flange on the side of my radiator.


Test fit, looks like it'll work... And it comes out without disassembling anything.


Now all that's left is a little more grinding, a skim coat of bondo and some paint inside and out. it's surprisingly rigid for only cloth and one layer of mat, more than enough to do what it has to do.


With a couple rounds of filler and a coat of satin black


Here is the side where it meets the mounting angle... T-nuts epoxied in, and Door insuilation felt (cheap at Ace HArdware) to protect metal on metal contact.


I'm going to slit some vacuum line and cover the top and bottom edges where it touches the radiator.

This was the first time I tried this technique, and it worked really easy... too easy, if I can do this, ANYBODY can. Next projects, reforming a '64 Riviera console to work in my Ford, and a super groovy Roth-style "body" for my minibike.

 

Very clever and simple good on ya

QQ

 

i used to work in a car audio shop and we made kick pannels , door panels and consoles with that process , but a fan shroud is a first fot me ! nice thinkin hope it does the trick for you !

 

outstanding! I need to make one of those for my ride.Thanks

 

Looks pretty simple. I may have to give this one a try. Awesome post...thanks.

 

Great idea. Much better than buying a universal and trying to make it work in your car. Thanks.

 

That opens up a lot of possibilities!

I was thinking of resinated unbleached linen over card, to make a Weymann-like fabric body. Stretchy T-shirt material might be easier.

How about wrapping the formwork in cling wrap? It might make subsequent stripping easier.

 

Looks great! Make sure it is stiff enough that it wont be pulled into the fan.

Whenever I build something like that I like to use fleece- It needs more resin and sanding, but it comes out pretty thick and stiff.

I use the thinner stuff if I plan to add alot of fiberglass cloth to it anyway.

 

cutting it is half was a good idea so you wouldnt have to yank the fan or anything else out. Well done

 

brilliant!

 

That's pretty awesome. I don't have any cooling problems, but I also don't have a fan shroud and I've been thinking about making one...nice work.

 

You could also use door edging for the top and bottom where it meets the radiator.

 

I had a hank of fuzzy stretchy fleece, I think I'll use it on the next project... it was a tossup as to which one to use, I figured this wouldn't have to be as strong as the minibike body... I had to twist and push the bottom half to get it around the fan and into position, and it didn't crack, so I'm thinking this'll be strong enough.

I forgot to mention the Polyester resin I used, came from a place down here called Fiberglass Coatings... I guess they are pretty big in the fiberglass world... they are in my backyard so I guess I'm lucky. The Home Depot BONDO brand stuff sucks and will make you REALLY hate fiberglass.

http://www.fgci.com/

The stuff I used is #124439 Polyester resin for hand layup... We (HotRodHabit and I) also used it to make a couple of t-bucket bodies...

 

Ha..now thats pretty slik there holmes..
did you give it a test run yet?
did it help?

 

I guess I know what I'm doing next month when I have a day off...very nice. Thanks for the idea. Let us know if it helped much.

 

cool tech, im gonna make one- thanks!

 

Great idea!.....I'm gonna do it for the wagon!......Good Tech!

 

I thought fan shrouds weren't traditional?

(ducks and runs for the door......)


Fantastic tech that anyone can do and is dirt cheap. That's what I'm talk'n about. Great writeup.

 

Looks great. Any special resin you used or just whatever pep boys had on sale? Is it very study?

I wonder if using vinyl would do anything different.

FWIW anybody looking for material to upholster your car joann's always has 40% off coupons, just poke around the website

 

Ive used the Bondo brand stuff in the can, if that's the brand they sell at Pep Boys, Home Depot, Walmart... IOt always comes out brittle, and it's hard to get it to soak into the mat/cloth because it starts out pretty thick. I think it's worth the price for the good stuff... Now I may use the cheapo Bondo filler, just because it's what I have laying around, and the finish on this is not critical.

Fan shrouds might not be traditional, but overheating is... Thanks so much for your opinion.

 

I was just being a smartass, didn't mean to come off as an ass. Someone would have said it eventually anyway.

So is it sturdy enough to maybe have bolted an electric fan to it?

 

Nice job Big Mike! Looks like it'll work out good. You never cease to amaze.

 

you gonna paint it flat black?

 

Are there any "rules" for how much clearance you need from the shroud to the edge of the fan blades, or how deep on the fan the shroud should be, or do you need to have a way for the air to escape from the shroud when on the road high speed? I've been wanting to add a shroud to my stock 49 chevy radiator after I added the AC condenser in front of the radiator and still running the stock mechanical fan, I've been thinking of making one out of sheet metal and welding it but not now...this is how I'm going to do it.

Great motivating thread...thanks.

 

Great tech Mike! I think that came out great and it should help out with your heat problem.

You want the fan to be about half in and half out of the shroud and you want about a 1/2 to an inch around the outside.

 

Thanks my brutha's! If I'm not right on those measurements, I'm within fudging distance... a little grinding here and there.

I may go nuts and paint it aluminum, or even the navy blue, would be a good place to try pinstriping... good edges to follow. Idano yet.

 

I think I would have put another layer of mat on it to hold up an electric fan... but I like my chrome fan.

 

Atta boy! Good job!
Love the polka dots! Bet Frankie Yankovich would too?