[BIG TUTORIAL] How to lightproof a wardrobe (for real this time)


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Jun 5, 2021
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I want to share a few things I learned while struggling to convert a regular 21 x 34 x 77" wooden wardrobe (with 2 leaves) into a growbox. The goal is to prevent ANY light from leaking out and preserve the wardrobe's appearance so that it won't look suspicious at first glance. I'll address a simple way of dealing with fan noise at the end of this post. I'm not going to discuss filters, ducting, fans, lamps and cutting intake/exhaust holes because there's plenty of guides about that.

Pic 1 is the kind of furniture I'm talking about. IMPORTANT: note that the door is supported by the bottom of the wardrobe when the hinges are gone. The door should should not jut out.
Pic 2 is the kind of setup I have inside, except the intake hole at the bottom is in the back, not the side.

My main takeaway from this project is that trying to keep the doors functional is pointless. You should remove the hinges completely.

I know this tutorial may look discouraging at first, but trust me - all you need is a little patience.

What you need:
- power drill
- screws (preferably pan heads) - about 20-30 short and 10 medium ones
- four 3-5" nails
- boxcutter
- two wooden battens, each slightly shorter than the total width of both leaves
- black PVC tape
- duct tape (yep, both kinds of tape. I mean it)
- four pieces of C-shaped ceiling profile (Pic 3. length: 2 x inside height of the wardrobe, 2 x inside width). Battens are OK too, but only if they're laminated because we'll be putting adhesive seals on them
- adhesive rubber seals (the kind in Pic 4 is the best. Total length needed: same as total length of profiles/battens mentioned above.
- cardboard box 1 (should fit on top of the wardrobe. about 20 x 15 x 10" is OK)
- cardboard box 2 (much smaller than box 1, but serves the same purpose for intake hole)
- (optional) wire cutters for cutting profiles
- (optional) saw for cutting battens
- (optional) file to smooth out the nails (Pic 5), which will let them slide in and out easily

Let's get to work!

DOOR (Pic 6)
- open one leaf, hold the other one in place and mark the line where the leaf meets the side, roof and bottom of the wardrobe (inside, of course)
- remove both leaves
- remove hinges, you won't need them anymore
- remove knobs/handles for the time being
- put both leaves as close to each other as possible on the floor
- apply two layers of PVC (NOT DUCT!) tape on the gap between them
- screw two battens to the leaves. don't screw them right next to the edges!
- screw the knobs back where they were

CUSTOM FRAME (Pic 7 is upper right corner, nail hole can also be seen)
- screw the profiles/battens to the sides, roof and bottom (a few milimeters deeper inside the wardrobe than the markings you made at the very beginning. depends how much the seals compress when squeezed)
- apply adhesive seals. make sure they meet in corners
- apply PVC tape between the frame and the wardrobe, pretty much necessary if you went with profiles instead of battens. you'll have an easier time if you cut the tape into pieces a few inches long.

NAILS AS BOLTS (Pic 8 is upper left corner seen from above)
- put the whole wardrobe (with door) horizontally on the floor
- put something heavy in all four corners of the door to compress the seals a little bit
- drill holes in the sides of the wardrobe so that the bit ALSO makes a hole in the middle of the side of the door. the holes' diamater should only be big enough to let you insert the nails. use a smaller diameter bit first and use a bigger one if the nail doesn't fit.

ROOF EXHAUST BOX (Pics 9, 10 and 11)
- cut the bigger box to make it look like this
- Pic 11 is closeup of those black plastic things I stuck near the exhaust hole because light would leak through the rift between the box and the roof

- the box should look more or less the same as the first one, except it should be flat enough to fit between the back of the wardrobe and the wall. Just use duct tape to tape it mount. You might want to add a wall inside to limit light leaks to absolute minimum.

Picture a scenario like this: both the lights and the fan are on. You have guests. One of them leaves the room where everyone's sitting and starts snooping around. They won't see the light because we did all this work to lightproof the box, but they might hear the fan. Just press "off" on the remote in your pocket and when everyone's back in the guest room, turn it on again.

The remote + socket combo I use works through two walls and about 15 yards. Make sure you test yours, though.

Let's wrap this up. If you have any questions, I'll answer them to the best of my ability.


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Jun 5, 2021
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This post is just for the remaining 3 pictures (I could only attach 10). I'd be grateful if a mod could add those to the OP and delete this post.


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Nov 7, 2008
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I build my grow rooms out of RMax.

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