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Unread 05-26-2011, 02:26 PM   #16
scrapman
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Quote:
Originally Posted by TBailey View Post
Looks good.The only thing I would have done differently would be to gelcoat it.Fiberglass and fiberglass resin are not water proof.
Why would it being "water proof" matter? Will the resin turn to mush if it gets wet?

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Unread 05-26-2011, 02:32 PM   #17
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I think you'll be quite fine without it being "waterproof". Fiberglass doesn't turn to mush in water. not at all. It is porous and will absorb water and dry out. much like wood. but I certainly dont see that being an issue with a fan shroud.
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Unread 05-26-2011, 02:35 PM   #18
Jim1611
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Now that's a great job my friend!! Nice to see some fiberglass work going on.
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Unread 05-26-2011, 02:36 PM   #19
Bakunin
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Very nicely done! And a great example of how critical a decent fan shroud really is.
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Unread 05-26-2011, 02:49 PM   #20
TBailey
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Quote:
Originally Posted by mikeumkc
I think you'll be quite fine without it being "waterproof". Fiberglass doesn't turn to mush in water. not at all. It is porous and will absorb water and dry out. much like wood. but I certainly dont see that being an issue with a fan shroud.
Fiberglass itself does not rot.Fiberglass resin will rot to an extent.It will only absorb water and dry so many times before it starts to crack and deteriorate.It will also get between multipe layers of glass and cause it to peel apart.At that point it wont be long before it comes apart and eats up the radiator.

The only reason I mentioned it is because it is something that is going to get wet.If you drive in the rain its getting wet.If you do a deep enough water crossing its getting wet.
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Unread 05-26-2011, 03:10 PM   #21
jcal73
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Quote:
Originally Posted by TBailey View Post
Fiberglass itself does not rot.Fiberglass resin will rot to an extent.It will only absorb water and dry so many times before it starts to crack and deteriorate.At that point it wont be long before it comes apart and eats up the radiator.

The only reason I mentioned it is because it is something that is going to get wet.If you drive in the rain its getting wet.If you do a deep enough water crossing its getting wet.
Thanks for the input.
I would think that a good coat of paint would seal it up enough to be ok.
If I'm in that deep of water something has gone terribly wrong!


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Unread 05-26-2011, 03:17 PM   #22
84scrambler
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I'm a little skeptical to think a fan shroud will help with over heating issues at freeway speeds. The purpose of a fan is to move a sufficient amount of air across the radiator but the use of a fan goes away when you get up to speed (stick your hand behind the fan at idle vs sticking it out of your window at 50 mph and there is no comparison). Adding a fan shroud aids the fan due to its size limitation but once you get up to speed you will have uniform air coverage across the radiator which should be much better then any automotive fan would provide. This makes me think your radiator is undersized for the size of your engine.

Perhaps there is more to it then what I am thinking. Please keep us posted as you get more hours driving it on the road.
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Unread 05-26-2011, 03:26 PM   #23
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Originally Posted by 84scrambler View Post
I'm a little skeptical to think a fan shroud will help with over heating issues at freeway speeds. The purpose of a fan is to move a sufficient amount of air across the radiator but the use of a fan goes away when you get up to speed (stick your hand behind the fan at idle vs sticking it out of your window at 50 mph and there is no comparison). Adding a fan shroud aids the fan due to its size limitation but once you get up to speed you will have uniform air coverage across the radiator which should be much better then any automotive fan would provide. This makes me think your radiator is undersized for the size of your engine.

Perhaps there is more to it then what I am thinking. Please keep us posted as you get more hours driving it on the road.
It's a four core radiator.....
Did you read my first post??
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Unread 05-26-2011, 06:04 PM   #24
84scrambler
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I skimmed through it again and can't find a mention of radiator size. Not important because I did see this written by you which I seemed to have missed the first time "It has too small a fan and not enough area open for the air to get through while on the road." reading that and looking at the picture makes complete sense for changing the shroud.

My personal experience I had a 4 core vertical copper radiator and had over heating issues. I switched to a two core cross flow aluminum radiator and temperatures dropped about 15 degrees. I didn't really have much of a fan shroud though.

i also saw an interesting design in a shroud, along the entire bottom it had spring flaps which would open up at highway speeds. Something to consider for future designs.
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Unread 05-26-2011, 06:15 PM   #25
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Originally Posted by 84scrambler View Post
I skimmed through it again and can't find a mention of radiator size. Not important because I did see this written by you which I seemed to have missed the first time "It has too small a fan and not enough area open for the air to get through while on the road." reading that and looking at the picture makes complete sense for changing the shroud.

My personal experience I had a 4 core vertical copper radiator and had over heating issues. I switched to a two core cross flow aluminum radiator and temperatures dropped about 15 degrees. I didn't really have much of a fan shroud though.

i also saw an interesting design in a shroud, along the entire bottom it had spring flaps which would open up at highway speeds. Something to consider for future designs.
I was thinking that you must have missed the part about the original fan and shroud.
The aluminum was out of the question because of money!
I was thinking of adding flaps or doors to the original, but I wanted to get away from an electric fan anyway.



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Unread 05-26-2011, 06:30 PM   #26
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Originally Posted by TBailey View Post
Fiberglass itself does not rot.Fiberglass resin will rot to an extent.It will only absorb water and dry so many times before it starts to crack and deteriorate.At that point it wont be long before it comes apart and eats up the radiator.

The only reason I mentioned it is because it is something that is going to get wet.If you drive in the rain its getting wet.If you do a deep enough water crossing its getting wet.
I'm going to pull it to refinish the paint/clean it up some.
How hard is it to use Gel Coat?
Can it be sprayed?
Do I have to paint it before or after or not at all?
Sorry for my ignorance, I've never used it.

Jeff
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Unread 05-26-2011, 07:26 PM   #27
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nice build.. i've been thinking of making some custom stuff out of glass but dont know much about it so that video will help out
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Unread 05-26-2011, 09:12 PM   #28
TBailey
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Quote:
Originally Posted by jcal73

I'm going to pull it to refinish the paint/clean it up some.
How hard is it to use Gel Coat?
Can it be sprayed?
Do I have to paint it before or after or not at all?
Sorry for my ignorance, I've never used it.

Jeff
Gel coat is simple to use but it has to be applied before the the top coat of paint.It can be sprayed once thinned.Thin it with acetone to about the consistency of water.If its not thin enough it will come out with a very rough texture.Be patient it will take three to four thin coats to get good coverage.Its also very easy to sand if you get a run or anything else goes wrong.Do not mix it in a plastic cup unless its a paint cup.The hardener will melt alot of plastics as will acetone.
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Unread 05-26-2011, 10:05 PM   #29
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You did a great job fabbing that shroud up!

How close of a tolerance do you have between the fan blades and the shroud itself? The reason I ask is because I've read that, if you go offroad and get a decent amount of flex, the fan can make contact with the shroud.

Fred
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Unread 05-27-2011, 06:07 AM   #30
jcal73
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Originally Posted by FLynes View Post
You did a great job fabbing that shroud up!

How close of a tolerance do you have between the fan blades and the shroud itself? The reason I ask is because I've read that, if you go offroad and get a decent amount of flex, the fan can make contact with the shroud.

Fred
Fred,
Thanks to you and all the others for the kind words.
I don't know about that much flex. I hope someone who has wheeled that hard can chime in.

It has about 1 inch or a little less between the blades and shroud.
Derale Performance tech support wanted 1/2 inch and covering only half of the thickness of the blades.

I'm pretty close on the covering half of the blades, but I made the template for the fan opening with one inch of clearance all the way around.
I wanted some "Fudge" room on the fan centering measurements.
It grew some in thickness with the 2 layers of glass and resin inside.
So it's a little less than 1inch and is almost centered on the fan.
Finding the center measurement of the fan in relation to the radiator core is hard to do.
You can't just use a small square and go from the center of the fan out to the core, this will make the center measurement high because of the tilt of the engine.
I used a length of heavy wire bent on 90deg to get the location from the core back to the center of the fan.
That’s where I drilled for the centering rod on the templates.

Sorry to be long winded.

Jeff
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