PRECURSOR
I have written this guide as a resource to those who need a bit of help making a nice performing and aesthetic shroud. I, myself, was frustrated when the only shroud guides I could find were quick 30min – 1hour jobs that involved cutting up a Tupperware container or quickly chopping up a fan duct for a crude design. This guide is not meant to copy anybody else, but I would DEFINITELY like to give a shoutout to Mastacator for his great pictures and Dryadsoul for all his assistance. I would also like to thank Villainstone for his friendliness and resources.
This guide is intended for those who are patient and willing to spend a few days perfecting their project. It is this patience that will make your result worthwhile.
I highly recommend that you read through this FAQ before you start your project.
MATERIALS
There are a few materials that are necessary to have to continue with the project.
PREPARATION
Now that we have all the materials, we need to get the measurements of the heater core and the fans going to be used. For the entire course of this FAQ, I will be using my measurements for the shroud I created. I will be using a mixture of both English and metric units, and I recommend that you do the same because often the measurements of some items are more exact in English units, and others are more exact in the metric form.
I determined the core itself (the ventilated part) was 6” X 240mm X 2”. My Delta fans were 120mm X 120mm X 1.5”.
STEP 1 – Cutting and Scoring the Base
Great, so we have all the measurements we need. We can start marking up the sheet metal to cut the base of the shroud.
First off, cut a 6” wide slice of sheet metal off of your big piece.
This piece is going to be Heater Core Height + 43.6mm (Pythagorean’s Theorem for a 40mm rise) + Fan Height + Fan Length / Width + Fan Height + 43.6mm + Heater Core Height.
So, for me, I made the length of this piece 2” + 43.6mm + 1.5” + 120mm + 1.5” + 43.6mm + 2” long. Make sure you mark every segment with a line like I have done.

When finished, do the same and mark each segment with a line on the back of the sheet metal. An easy way to do this is by holding the sheet metal on its side and place marks on the side of the sheet metal that join the lines you have already made on the front. When flipped over, there should be noticeable point marks that you can connect to make the back lines.
After you’ve got all your base lines down, go out and cut out this piece. I’m not going to go into detail here, as that is a whole different guide, but I will tell you what I did. I used a Dremel to cut out the base, then a bench grinder to straighten the edges, and finally a file to smooth the edges.
Save your scraps, you will need them later.

Now that it is cut out we are going to score the lines with a utility knife. Choose one side of the metal to be the front, and another to be the back.
On the front, use the utility knife to score lines (left to right) 2 and 5. On the back, score the rest of the lines. When scoring, you are basically just running the knife down the lines you created. 3 or 4 passes should be enough.
STEP 2 – Bending!
Yay! Bending! Huzzah!
Well, anyway, to bend you are going to first want to prepare a proper bending station. You WILL want a sharp edge (metal preferably) and a piece of thin metal with a few clamps to lie over the top of the sheet metal to bend.

As shown, I used my table saw edge as the edge to bend on. Over the top, I laid a carpenter’s square over sheet metal, with two clamps holding it down.
Alright, so our first bends are going to be right angles on the two center (3 and 4) lines. You want to bend downward, towards your score on the backside of the sheet.
Align the line on the sheet metal with the edge of the table, and place the overlying metal flesh with the edge as well. Clamp it down and start bending.
When bending, you should keep you hands as close to the line to score as possible. You don’t want to warp your metal.
When finished your metal should look like this:

Your next bend is going to be on lines 2 and 5, bending against your score on the front side. You are going to be bending these at roughly a 30 degrees angle.
When finished, it should look something like this:

Go ahead and take a break to see how your fans fit in the shroud. Mine look like this:

The last bend is going to be on the remaining lines 1 and 6. You will want to bend, again, at roughly a 30 degrees angle toward your score on the backside of your base metal.

Great, we’re all done with the bending! After a bit of hand molding, you should be able to fit your shroud on your heater core like so:


STEP 3 – Cutting the Blowholes
Flip your shroud over and place in your fans. Through the screw holes of your fans, use a nail and a hammer to mark where you will drill your screw holes.
With your screw holes drilled, find a 120mm fan grill and align it with the screw holes on the top of the shroud. Use a pencil to trace around the edge of the outer 120mm grill ring.

Cut these holes out and you should have something like this:

STEP 4 – Making the Side Panels
With a scrap of your sheet metal, use your ruler and Sharpie to draw a piece that is 17.5mm + Heater Core Width + 17.5mm long. So, for me, it’d be 17.5mm + 6” + 17.5mm.

Then draw a line that is a 10mm rise from the bottom.

Next, draw a line that has a 50mm rise from the bottom (or a 40mm rise from the line you just drew).

After this, draw a line diagonally, from upper inner corner to the lower outer corner of the two rectangular boxes formed on the left and right. This is easier to explain in the picture below.

Finally, make two 17.5mm points coming in from the two rectangular boxes on the 50mm line. Draw a diagonal line from these points to the lower corner of the big middle rectangular box. Again, this is easier to explain in the pictures.


Cut as shown…



STEP 5 – Bending and Installing the Side Panels
So, now that you’ve made two of those panels, proceed to score the two flaps on each one.
Then bring the scored panels over to your bending station and bend each flap a right angle toward your score.
The end result:

Now you are going to install these in your shroud.
Go ahead and screw in your fans, and then place the side panels in the shroud base. Then place the whole thing on your heater core.
With a little bit of hand molding and a few clamps you should be able to get it to fit right. If you followed the directions correctly, the side panel should cover the entire exposed ventilated part of the heater core and part of the fans mounted on the shroud base. The flaps should also be flesh against the shroud base.

Great! Now we just have to secure this thing. I used rivets, but it is also possible to use bolts. The best way to go about this step is by using a few small clamps to clamp the shroud together to form the correct shape you want after you rivet or bolt it together.
Once you have it clamped, start your drilling and riveting / bolting.

STEP 6: Finished!
When all your riveting / bolting is finished…you’re done! Feel free to grab a refreshing beverage of your choice at this moment and relax.
When you put the shroud on your heater core, it should already be a tight fit that shouldn’t require the use of any more securing. If you DO need a better method to secure the thing, you can use mastacator’s method of bending rivet tails into “U” shapes and hooking them to the underside of the core and shroud.





It is your choice, at this point, if you want to paint the shroud. I am not going to go into details here, as there are many great paining guides.
Thank you for all your support! If you have any comments or revisions to add, please tell me!
I have written this guide as a resource to those who need a bit of help making a nice performing and aesthetic shroud. I, myself, was frustrated when the only shroud guides I could find were quick 30min – 1hour jobs that involved cutting up a Tupperware container or quickly chopping up a fan duct for a crude design. This guide is not meant to copy anybody else, but I would DEFINITELY like to give a shoutout to Mastacator for his great pictures and Dryadsoul for all his assistance. I would also like to thank Villainstone for his friendliness and resources.
This guide is intended for those who are patient and willing to spend a few days perfecting their project. It is this patience that will make your result worthwhile.
I highly recommend that you read through this FAQ before you start your project.
MATERIALS
There are a few materials that are necessary to have to continue with the project.
- Sheet metal (26 or 28 gauge, 3ftX3ft or more)
- Durable ruler
- Fine tip sharpie pen
- Philips screwdriver
- 2X 120mm fans
- Rotary tool or jigsaw to cut (I used Dremel)
- Power Drill
- Small screws or rivets and rivet gun
- A few clamps
PREPARATION
Now that we have all the materials, we need to get the measurements of the heater core and the fans going to be used. For the entire course of this FAQ, I will be using my measurements for the shroud I created. I will be using a mixture of both English and metric units, and I recommend that you do the same because often the measurements of some items are more exact in English units, and others are more exact in the metric form.
I determined the core itself (the ventilated part) was 6” X 240mm X 2”. My Delta fans were 120mm X 120mm X 1.5”.
STEP 1 – Cutting and Scoring the Base
Great, so we have all the measurements we need. We can start marking up the sheet metal to cut the base of the shroud.
First off, cut a 6” wide slice of sheet metal off of your big piece.
This piece is going to be Heater Core Height + 43.6mm (Pythagorean’s Theorem for a 40mm rise) + Fan Height + Fan Length / Width + Fan Height + 43.6mm + Heater Core Height.
So, for me, I made the length of this piece 2” + 43.6mm + 1.5” + 120mm + 1.5” + 43.6mm + 2” long. Make sure you mark every segment with a line like I have done.

When finished, do the same and mark each segment with a line on the back of the sheet metal. An easy way to do this is by holding the sheet metal on its side and place marks on the side of the sheet metal that join the lines you have already made on the front. When flipped over, there should be noticeable point marks that you can connect to make the back lines.
After you’ve got all your base lines down, go out and cut out this piece. I’m not going to go into detail here, as that is a whole different guide, but I will tell you what I did. I used a Dremel to cut out the base, then a bench grinder to straighten the edges, and finally a file to smooth the edges.
Save your scraps, you will need them later.

Now that it is cut out we are going to score the lines with a utility knife. Choose one side of the metal to be the front, and another to be the back.
On the front, use the utility knife to score lines (left to right) 2 and 5. On the back, score the rest of the lines. When scoring, you are basically just running the knife down the lines you created. 3 or 4 passes should be enough.
STEP 2 – Bending!
Yay! Bending! Huzzah!
Well, anyway, to bend you are going to first want to prepare a proper bending station. You WILL want a sharp edge (metal preferably) and a piece of thin metal with a few clamps to lie over the top of the sheet metal to bend.

As shown, I used my table saw edge as the edge to bend on. Over the top, I laid a carpenter’s square over sheet metal, with two clamps holding it down.
Alright, so our first bends are going to be right angles on the two center (3 and 4) lines. You want to bend downward, towards your score on the backside of the sheet.
Align the line on the sheet metal with the edge of the table, and place the overlying metal flesh with the edge as well. Clamp it down and start bending.
When bending, you should keep you hands as close to the line to score as possible. You don’t want to warp your metal.
When finished your metal should look like this:

Your next bend is going to be on lines 2 and 5, bending against your score on the front side. You are going to be bending these at roughly a 30 degrees angle.
When finished, it should look something like this:

Go ahead and take a break to see how your fans fit in the shroud. Mine look like this:

The last bend is going to be on the remaining lines 1 and 6. You will want to bend, again, at roughly a 30 degrees angle toward your score on the backside of your base metal.

Great, we’re all done with the bending! After a bit of hand molding, you should be able to fit your shroud on your heater core like so:


STEP 3 – Cutting the Blowholes
Flip your shroud over and place in your fans. Through the screw holes of your fans, use a nail and a hammer to mark where you will drill your screw holes.
With your screw holes drilled, find a 120mm fan grill and align it with the screw holes on the top of the shroud. Use a pencil to trace around the edge of the outer 120mm grill ring.

Cut these holes out and you should have something like this:

STEP 4 – Making the Side Panels
With a scrap of your sheet metal, use your ruler and Sharpie to draw a piece that is 17.5mm + Heater Core Width + 17.5mm long. So, for me, it’d be 17.5mm + 6” + 17.5mm.

Then draw a line that is a 10mm rise from the bottom.

Next, draw a line that has a 50mm rise from the bottom (or a 40mm rise from the line you just drew).

After this, draw a line diagonally, from upper inner corner to the lower outer corner of the two rectangular boxes formed on the left and right. This is easier to explain in the picture below.

Finally, make two 17.5mm points coming in from the two rectangular boxes on the 50mm line. Draw a diagonal line from these points to the lower corner of the big middle rectangular box. Again, this is easier to explain in the pictures.


Cut as shown…



STEP 5 – Bending and Installing the Side Panels
So, now that you’ve made two of those panels, proceed to score the two flaps on each one.
Then bring the scored panels over to your bending station and bend each flap a right angle toward your score.
The end result:

Now you are going to install these in your shroud.
Go ahead and screw in your fans, and then place the side panels in the shroud base. Then place the whole thing on your heater core.
With a little bit of hand molding and a few clamps you should be able to get it to fit right. If you followed the directions correctly, the side panel should cover the entire exposed ventilated part of the heater core and part of the fans mounted on the shroud base. The flaps should also be flesh against the shroud base.

Great! Now we just have to secure this thing. I used rivets, but it is also possible to use bolts. The best way to go about this step is by using a few small clamps to clamp the shroud together to form the correct shape you want after you rivet or bolt it together.
Once you have it clamped, start your drilling and riveting / bolting.

STEP 6: Finished!
When all your riveting / bolting is finished…you’re done! Feel free to grab a refreshing beverage of your choice at this moment and relax.
When you put the shroud on your heater core, it should already be a tight fit that shouldn’t require the use of any more securing. If you DO need a better method to secure the thing, you can use mastacator’s method of bending rivet tails into “U” shapes and hooking them to the underside of the core and shroud.





It is your choice, at this point, if you want to paint the shroud. I am not going to go into details here, as there are many great paining guides.
Thank you for all your support! If you have any comments or revisions to add, please tell me!








