Need encouragement to cut walls

[bbarry]

Can someone please pop into my build thread and confirm that my thoughts on my hatch/wall notch are okay? I haven't received any feedback over there. While I've looked through a number of older threads, I'm about ready to cut the notch and would like an expert opinion. In this case, I'll consider anyone other than me an expert! Thanks in advance!

http://www.tnttt.com/viewtopic.php?t=27225&start=45

Brad

[Mark McD]

Barry,
The thickness of your skin(s),plus half the thickness of your seal should give you the depth of your notch. Even if you overcut the notch,(too deep), you can add a thicker seal or you could also cut thin strips of wood to get the hatch to match up. Give me a minute I'll post some drawings.

[bobhenry]

Brad

It ain't real clear what you are asking ! I read and read and reread and then I was thoroughly confused. Are you concerned with the side wall gasketing or how to seal the hinge area?

I will toss out what I did and hope it will help. I found a garage door bottom seal. It's kinda thin and floppy and I rolled it into a tube ( kinda sorta ) and fastened it with large headed nails. It forms a "c" shape with the bowl facing outward. For my hatch I placed weathermate vapor barrier ( tyvech type mat'l) down just before I installed the hinge leaving it in a loose blouse. I then attached the hinge and placed the skins over the hinge. My final weather barrier was rubbermate anti skid rubber shelf liner ( rubber roofing would work well also) I bloused this upward in a hump so water would drain and capped top and bottom with 1/4 x 1" aluminum flat stock. 2 years in the weather 24 - 7 and never a leak.

[bbarry]

It ain't real clear what you are asking!

Sorry, what I was wanting some confirmation on was the depth of my notch. What makes it a little different from normal is that my roof has ONE layer of 1/8" ply while the hatch will have TWO. I want to make certain that the two line up nicely. In reality, I think that the gasket will cover a multitude of sins here as it can compress to fit (and as Mark said...I can always order a thicker gasket).

I was thinking of notching 1/4" from the edge. This will allow 1/8" for the compressed gasket and 1/8" for the first layer of plywood. That should get me back up the level of my frame. The 1/8" ply on the roof and the second layer of ply on the hatch should match up then...right?

Brad

[bobhenry]

Sounds like you got it figured out !

Good luck with your build

[Mark McD]

I'm not sure if this helps.
like I said if you overcut the depth of the notch you can add a thicker seal or cap the trailer side panel with the appropriate thickness wood strip under the galley moulding that goes on the edge. I actually prefer this method because it does two things- it seals the raw plywood edge and it gives you some soild wood under the aluminum moulding to screw into. in this case it's easier to add material, - weatherstripping or wood, if you find your notch is too deep than it is to whittle away at the sides after they've been installed trying to get the hatch to drop in.

[Mark McD]

Good luck ... don't sweat it..anything can be fixed.

[bbarry]

[img] in this case it's easier to add material, - weatherstripping or wood, if you find your notch is too deep than it is to whittle away at the sides after they've been installed trying to get the hatch to drop in.

Come to think of it, that's probably true. I tend to think: cut a little, you can always cut more. But in this case, I think you're probably right.

Thanks both of you for your help!

Brad

[tonyj]

I would suggest 3/8" on the notch and at least 1/4" gasket, maybe even 3/8" or 1/2".

Your math and logic is correct, but the 1/4" notch for 1/8" ply and 1/8" gasket means no compression on the gasket. Depending on the accuracy of your cut, the springback on the hatch, and the alignment of the stars, you want to make sure the gasket compresses. That means the sum of the thicknesses of the ply and hatch need to be more than the depth of the notch. Water and dust won't be sealed out unless the gasket compresses.

[bbarry]

I would suggest 3/8" on the notch and at least 1/4" gasket, maybe even 3/8" or 1/2".

Your math and logic is correct, but the 1/4" notch for 1/8" ply and 1/8" gasket means no compression on the gasket. Depending on the accuracy of your cut, the springback on the hatch, and the alignment of the stars, you want to make sure the gasket compresses. That means the sum of the thicknesses of the ply and hatch need to be more than the depth of the notch. Water and dust won't be sealed out unless the gasket compresses.

Sorry...again I wasn't clear!

I was thinking of using Grant's hatch seal. It's .4" high and I seem to remember him posting somewhere saying it compressed down to very little. I was figuring 1/8" for the compressed height of the seal (not the total height). Maybe I need to figure a bit more. Obviously, a thicker, squishier (technical term) seal means more forgiveness in the accuracy of my work and the alignment of stars!

Brad

[aggie79]

The quick answer is the seal will compress to 1/16".

I asked the same question to Grant on his forum site: http://www.forum.teardrops.net/simpleforum_pro.cgi?fid=02&topic_id=1228241859, but I do plan to leave a "gap" of 1/8" to 3/16" for the seal.

[bbarry]

The quick answer is the seal will compress to 1/16".

I asked the same question to Grant on his forum site: http://www.forum.teardrops.net/simpleforum_pro.cgi?fid=02&topic_id=1228241859, but I do plan to leave a "gap" of 1/8" to 3/16" for the seal.

Ah-ha! This is exactly what I needed! I'll proceed with confidence now! Thanks everybody!

Brad

[Senior Ninja]

Hey Bard,
Have courage man.
It took me two hatches before I got it right. And from what I read that's not all that uncommon. I might even try a third one if I ever get ambitious. Usually when I get that ambitious I take a nap until that urge goes away.
LOLOLOLOL
Steve

[bbarry]

Usually when I get that ambitious I take a nap until that urge goes away.

I'm quite familiar with that!

Brad