Hood vent rain pans
 

hello everyone this is my first atempt at a tech article so let me know if you have any questions or if i missed anything
i've seen the installation of hood vents here on the forum and have added them to my 89 waggie, here in florida we have two things in abudance heat, and rain so i needed to protect my engine especially the electrical from the moisture, when it rains here it pours:boat:


these are the tools you will need but you can use a ball pein hammer in place of the body hammer i used you will need c-clamps to hold everything while it's being formed. you will also need an adhesive. I used a type used in construction and it works pretty well it's made by locktite i believe it's available at lowe's the marker, tape measure, pliers, and snips are pretty common. as for the air drill i used it because i had it an electric or cordless will work just as well. what's not shown is the drill bits , these will be to each person's individual needs. along with these you will also need a pop rivet tool and rivets (i recommend 3/16") and screws to attach the pans to the hood reinforcement structure (i used #14 by 1/2")

This is the cut-out from my hood with some general ideas and measurements written on it to help me remember:001_unsure: basically i want to make my pans slightly larger than the vents so this will give me a basic size to work from you can also measure your vents and use the measurements or even a posterboard cut-out to work from
at this stage you need to look for anything in the engine compartment that will be in the way. i had to modify the shape of one pan to clear my coolant resevoir for instance
by the way as it says don't forget you have to make a right and a left version, not doing so would at best make you :wallbash:

you will also need to make two plywood forms that will be the final size of your pans basically i made my forms 3/8" larger on all sides
this is what's known as a hammerform and you can make some pretty complex shapes using it. the trick is to make it as accurate as you can, and to work the metal slowly remember the metal will form only as well as your hammerform:thumbup1:

you of course will need your metal cut to size. i am using aluminum that we use for semi-trailer roofs it is about .040" i believe and is very easy to form
If you look around you should be able to find something similar i believe the designation is 6061-t4 if you go to a metal shop (PLEASE correct me if i'm wrong i don't want to give anybody the wrong info)

I cut my aluminum 3/8" larger than my hammerform on three sides, the side that the drain will be on i cut 2" larger because i will wrap it completely around the form because this is where the water will channel to to be drained

you also need to figure what size tubing you will use to drain I chose 3/4" clear tubing

now take your aluminum and one piece of your hammerform this will be the section of the form you will shape the metal to so when you do the next piece make sure you flip it

place the form on the aluminum in the position you determined earlier in my case it was 3/8" from three sides and the side on the two inch side it fell wherever

because the form is already the right size the 3/8" makes the sidewalls, on 2" side we will shape it completely around the form

now carefully flip over the aluminum and the form and lay the top on i usually eyeball it, this section basically keeps the pan flat while forming so get it as close as you can and you should be alright

then c-clamp it with the c-clamp screws facing up towards the top

this set of pictures shows the basic forming
work the metal slowly up to each of your clamps then bump your clamps towards the formed side and continue this way the metal remains under pressure during the entire process

when you come to a corner use the edge of your hammer to work right up to the next edge then slowly work over you need to control the metal on both sides while doing this or it will only bow out work a little on each side and use the edge of your hammer

on the 2" side you will need to notch out a section and then form it completely around the form once this is done to your satisfaction you need to repeat the process for the other side
REMEMBER: mirror your pieces you don't want :oops:

this series of photos shows the basic forming of the spout
first is the tools aside from the material you will need a rod, etc. the size of your tubing and a hammer

this is a big freakin' nail that i use for different things and it just happens to be 3/4" in diameter

fasten your rod or whatever in a vise or anything else that will hold it solid I'm using a block of steel that i made up to do this sort of thing with

slowly start forming a cylinder out of the aluminum work a little at a time sometimes you will have to freeform then round it back out use your hands if you need to just be careful, it will cut you if your not careful (trust me between sheetmetal, aluminum , and stainless steel i've lost track of the number of stitches i've had.....i'm not joking)

this series shows the tube after trimming

next cut a series of slots in one end of the tube they don't have to be super deep

next use the pliers to bend them over 90 degrees the final photo shows what you should have at this point two tubes and two pans

next step is where the size of your cylinders is important as i said mine are 3/4" roughly because they are wrapped on themselves they will fit tightly in a 3/4" hole so first step is to drill your hole in the pan wherever you want the water to exit i put mine at the rear but on hind-sight i wish i had put them towards the front because of the natural slope of the hood:oops:
once you have the tubes in the holes you need to tap down the flanges we made so everything is flat you can use whatever you have i used a 1" drive 2 1/2" socket but a piece of pipe or even a piece of wood with a hole in it will work

once that is done slip your tubing in place (a bit of soap helps here) and slide it tightly up against the pan

then i used the adhesive to not only attach the tubes but to fill any gaps or holes and let it dry

the last picture shows the pans from the bottom i have attached strips of aluminum with one pop rivet so that they can be turned in any direction the goal is to bend these to get my air gap and have them attach with screws to the reinforcement structure on the bottom of the hood so no fasteners will be seen

as you can see i've attached the pans to the hood with my vents centered over them at this point i,m tweaking everything to line up and give me an air gap all around i had to adjust a few things as i went but my vents are relatively large because i removed a damaged part of my hood when i installed them (caused by a limb from the oak i found it under no doubt:icon_sad:)

your vents size as well as what you have in the way under the hood is going to effect what you need to do

thats why it's best to plan ahead when you make your hammerform by the way your hoses will need to be cut and roughted out of the way of exhaust etc. mine are cut so that with the hood open they are still trapped between th brake lines on the drivers side and the heater hoses on the pass. side as i close the hood i just make sure they slide down in the proper direction and that keeps them out of harms way

as far as the gap between the pans and hood i just got as much as i could i can already see that a little mod here and there will give me a bit more but remember heat rises it will find it's way out

here are some shots of my vents and pans from the outside i'm really happy with them and have seen a big difference in my temps. it rained pretty hard last night and everything seemed to do what it was supposed to. I had to do a road call today so got some interstate time in everything was solid at 70 mph
(that was the speed limit:001_unsure:)
i hope you were able to get something out of this you can use the hammerform method to make a lot of different parts with some pretty complex shapes, and this is by far not the only or simplest method but you can build your metalworking skills pretty fast with projects like this.

Thanks