John Sayers' Recording Studio Design Forum Archive

Hi all, this is my first time posting here. I've been going though past threads trying to find answers to every question I can think of about building a small isolation booth to record voiceovers. Part of the plan is to mount a solid-core door slab with two layers of .75" MDF secured to it, and I have some questions about sealing it properly. I've seen car trunk seals mentioned in other threads, and I checked out Door Seals - Pix (DoubleHelix) in the Reference Area -- only every image has been replaced with the word "Image." Can anyone else see those pictures, or are they history? I'm having a hard time visualizing what he accomplished without them.

How much would it cost to seal the door using DoubleHelix's method compared to using this door seal kit? It has a threshold and an automatic door bottom, which I'll need anyway, right? I found it in the Reference Area here. What DoubleHelix did might be beyond my skills as a carpenter, anyway, so maybe this kit is the way to go.

I'm also thinking of designing the booth so I can eventually break it down and comfortably transport the entire thing in the event that I need to move. The door slab will probably be 80-100 lbs and the two door-sized sheets of MDF would probably be 100 lbs total. Would I be able to drill 1/4" holes straight through and then bolt the two sheets of MDF to the door so they can eventually be removed? I'm thinking of adding some sort of sealant like silicone around the inner perimeter of the door and possibly around the holes before securing the MDF to it in order to create an airtight seal around everything. Or would the holes basically negate the reason for having a solid-core, hole-free door in the first place?

Thanks!
Brian

Hi Brian, and Welcome!

every image has been replaced with the word "Image."

Unfortunately, they are gone forever. That's why one of the forum rules is to upload your images to the forum, not just link to off-site images... because off-site locations can change, or move, or disappear entirely. Sadly, there's nothing we can do to get those images back, since they never were here on the forum at all: just links.

Sorry!

plan is to mount a solid-core door slab with two layers of .75" MDF secured to it

That's going to be heavy! It's a good door, with decent mass, and that's fine... but it is going to need some tough, rigid framing around it to hold it in place and prevent it from warping, twisting, sagging, etc. over time, and especially as it is being opened and closed. You are going to need several heavy-duty hinges to deal with that. I normally use five hinges: two close together near the top, two close together near the bottom, and one in the middle. Also, you will need an automatic door closer: Trying to close such a heavy door by hand is dangerous for both you and the door jambs: If you get your fingers in the way while it is closing fast, that can do some serious damage to you. And if it hits the jamb too hard, that can mess up the jambs and seals. A door closer will take care of closing it smoothly, slowly, then applying the necessary pressure to the seals, to keep them tight.

an automatic door bottom, which I'll need anyway, right?

Right! You need at least one, and preferably two full-perimeter seals: top, bottom and both sides. Those seals should end up being continuous and unbroken when the door is closed.

I normally recommend seals from Zero International. Expensive, but good. They have several different types, but I like the ones that can be adjusted any time you need to, since the door WILL sag slightly over time anyway, even with good framing, so adjustable seals is a good idea. They are simple to fit, and simple to adjust. But not cheap!

Would I be able to drill 1/4" holes straight through and then bolt the two sheets of MDF to the door so they can eventually be removed?

It's possible, provided that you seal the holes very well, but it would not look very pretty! I would suggest just screwing it together, countersinking the screws, then putting easily removable trim over the screw heads.


- Stuart -

That's going to be heavy! It's a good door, with decent mass, and that's fine... but it is going to need some tough, rigid framing around it to hold it in place and prevent it from warping, twisting, sagging, etc. over time, and especially as it is being opened and closed. You are going to need several heavy-duty hinges to deal with that. I normally use five hinges: two close together near the top, two close together near the bottom, and one in the middle. Also, you will need an automatic door closer: Trying to close such a heavy door by hand is dangerous for both you and the door jambs: If you get your fingers in the way while it is closing fast, that can do some serious damage to you. And if it hits the jamb too hard, that can mess up the jambs and seals. A door closer will take care of closing it smoothly, slowly, then applying the necessary pressure to the seals, to keep them tight.

Thanks for pointing out the potential hazard a door like this could be! I always looked at the door closer as a necessity since there shouldn't be any holes in it for a latching mechanism. I never really viewed it in terms of safety until now.

I actually already have a heavy-duty door closer. Its maximum load, though, is only 188 lbs, which wouldn't have worked for the door/MDF combo I described earlier. It turns out I messed up on the math -- 36"x80" of .75" MDF is around 70 lbs. The .5" MDF would be closer to 50 lbs, so I'm probably going to go with that instead of .75", with Green Glue sandwiched in between. With the pull handle and push plate, I'll be cutting it close, but I think the final result will be around 188 lbs.

I think I have the hinges covered, thanks to Gregwor. He mentioned the Hager BB1168 hinges in another thread, and I spoke to one of their representatives that said, "as long as you do not exceed 225lbs you should be ok with 3 hinges." I'll probably go with more, though, just to be safe.

It's possible, provided that you seal the holes very well, but it would not look very pretty! I would suggest just screwing it together, countersinking the screws, then putting easily removable trim over the screw heads.

This is probably what I'll end up doing. Thanks for the suggestion. I found some white plastic hole plugs that would look a lot better than exposed screw heads.