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Weather stripping

PostPosted: Mon Apr 20, 2015 5:08 pm
by OP827
I am at the point in my build when I need to finalize weather stripping details as it will determine certain dimensions.

Could you please share such sources of information that have detail drawings of various junctions weatherstripping of RVs, TTTs, etc.?

Thanks for help. :worship:

Re: Weather stripping

PostPosted: Mon Apr 20, 2015 7:45 pm
by OP827
bump.. :D

Re: Weather stripping

PostPosted: Mon Apr 20, 2015 8:05 pm
by KCStudly
I bought my hatch seal from Grant at Lil Bear Tag-Alongs

I should have taken it out of the shipping envelope right away though, as it now has kinks and the adhesive peel ply has separated in these locations (I hope the adhesive has not dried up in these locations). I rewound it recently and am hopeful that it bounces back. It is very soft, thin wall and collapses readily, going to almost nothing.

For the side doors I selected an internal flange and Trim Lok Trim Seal purchased from McMaster-Carr (they sent me a 1 ft sample of an initially larger bulb size... perhaps because I do regular business with them thru my work... which allowed me to see that I needed a smaller bulb size). This is a quality product on par with what OEM automotive manufacturers use. I selected the 3/16 grip and 3/8 bulb size with the bulb in the "E" location (at 90 degs on the same side as the channel rib seal), used 5 mm (3/16) ply for the flange and two layers of the 5 mm for the spacer.

Can't really speak to performance yet, but I figure that has more to do with installation configuration and technique than anything.

I realize that you will probably have to find sources closer to home, but at least you can have an idea of what options you may want to look into.

Convention says that you only want to compress a seal about 1/4 to 1/3 of its free height, in order to preserve its springiness and maintain a long lasting seal.

Re: Weather stripping

PostPosted: Mon Apr 20, 2015 8:18 pm
by OP827
KCStudly wrote:
...
Convention says that you only want to compress a seal about 1/4 to 1/3 of its free height, in order to preserve its springiness and maintain a long lasting seal.


Thanks! Since I have a variety of shorter vertical and long horizontal seals with my foldable design your above advice is really helpful. I am new to this weatherstripping design and have no idea how to design a gap seal properly.
If I have a horizontal gap between lifting roof and lower wall that is ~10 ft long, what size of seal would be proper to use? I guess that the longer the seal, the more movement is expected on the road or under changing wind. Should I try to estimate the possible movements based on the structure rigidity and go from there, I figure? Thanks KC.

Re: Weather stripping

PostPosted: Mon Apr 20, 2015 8:20 pm
by OP827
I think for long seal I maybe better off with magnetic seal strip :thinking:

Re: Weather stripping

PostPosted: Mon Apr 20, 2015 8:52 pm
by KCStudly
For a lifting roof that clam shells over the lower cabin?

Some people will use garage door seals that are much bigger and have either a large flap or a big soft bulb.

If I were doing something like that I would try to have raised sealing surfaces at the open and closed positions so that the seal registered more positively in those locations but did not sweep so hard, or even touch at all over the transition. My thinking is that this would save on wear and tear on the seal and would help keep the finish on the sides from becoming scratched or discolored where the seal swipes by.

Re: Weather stripping

PostPosted: Mon Apr 20, 2015 10:25 pm
by OP827
KCStudly wrote:For a lifting roof that clam shells over the lower cabin?

Some people will use garage door seals that are much bigger and have either a large flap or a big soft bulb.

If I were doing something like that I would try to have raised sealing surfaces at the open and closed positions so that the seal registered more positively in those locations but did not sweep so hard, or even touch at all over the transition. My thinking is that this would save on wear and tear on the seal and would help keep the finish on teh sides from becoming scratched or discolored where the seal swipes by.


Yes, it is generally a clam shell over the lower cabin. Garage door seal sounds like a good idea, but i am having difficulty to visualize what do you mean by raised sealing surfaces and positive regisered seal, a little hand sketch would help a lot. Thanks KC!

Re: Weather stripping

PostPosted: Mon Apr 20, 2015 10:42 pm
by OP827
Very very roughly, this is the kind of arrangement I am looking to seal. Interested whether there some standard detail sketch being discussed before...
Image

Re: Weather stripping

PostPosted: Tue Apr 21, 2015 9:14 am
by OP827
KC, thanks for the trim lock link, they do have some catalog and design considerations discussed there, it is a good starting point.

Re: Weather stripping

PostPosted: Tue Apr 21, 2015 9:33 am
by OP827
In my quest for weather stripping detail design I found this new design hinge, could be a good solution for TD hatch hinge and seal: http://www.mooreindhardware.com/pdf/CEN ... ge-PDF.pdf

Re: Weather stripping

PostPosted: Tue Apr 21, 2015 1:58 pm
by KCStudly
My assumption, and from looking back at your initial sketches on your build thread, was that your lifting roof sides would be outside of your lower fixed walls, and that you are asking for a way to seal between the two, side by side (like in Sect A of the Winter Warrior plans, pg 7).

In your sketch above, I'm assuming that this is for the folding hard wall filler sections. I would think that the 'D' shaped hatch seal would work well there; just dado a groove wide enough for the seal to compress and to prevent the seal from over compressing.

For the sweeping side seal, such as for a Winter Warrior, upon review it looks like the plans just call for a brush style sweeper. This is where I was thinking that people have used the garage door style seals (IIRC). My thought was to position the seal so that it does not contact the sides, and to have raised areas, or beveled ramp strips, where the seal comes to rest at the ends of the hatch travel. These ramps would take up the extra clearance and give the seal a spot to land. With only 6 mm (or 1/4 inch) clearance between the inner and outer that might not be very practical and still have room for both clearance and seal compression.

Re: Weather stripping

PostPosted: Tue Apr 21, 2015 4:29 pm
by OP827
KCStudly wrote:My assumption, and from looking back at your initial sketches on your build thread, was that your lifting roof sides would be outside of your lower fixed walls, and that you are asking for a way to seal between the two, side by side (like in Sect A of the Winter Warrior plans, pg 7).

In your sketch above, I'm assuming that this is for the folding hard wall filler sections. I would think that the 'D' shaped hatch seal would work well there; just dado a groove wide enough for the seal to compress and to prevent the seal from over compressing.

For the sweeping side seal, such as for a Winter Warrior, upon review it looks like the plans just call for a brush style sweeper. This is where I was thinking that people have used the garage door style seals (IIRC). My thought was to position the seal so that it does not contact the sides, and to have raised areas, or beveled ramp strips, where the seal comes to rest at the ends of the hatch travel. These ramps would take up the extra clearance and give the seal a spot to land. With only 6 mm (or 1/4 inch) clearance between the inner and outer that might not be very practical and still have room for both clearance and seal compression.


Thanks KC, I did not know about those WW plans. My design has evolved from original boxy trailer with top over the walls to a streamlined clam shell resting ON the walls to save on the trailer width and streamline the shape. I will have mainly three types of seals:
1. As shown above on rough sketch. If I understand your above information correctly, I can use a D-cell glued to an upper wall with a rabbet on the lower wall to match it as you have advised. Pretty much the same as shown on Winter Warrior plan page 6:
Image

This is very important seal between the roof shell and lower wall (when folded) and hard wall filler sections (when unfolded). It will be 10 ft long. Do you know where I can find design compression forcec for each d-cell seal in catalog so I can select the proper one based on the roof weight? .

2. Brush type and blade type for vertical sliding detail, WW Plans Page 7. I think I can figure out how to select those.

3. Blade compression on vertical seals of filling hard walls. I will size them based on expected tolerances and movements.

Cheers :) :thumbsup:

Re: Weather stripping

PostPosted: Tue Apr 21, 2015 5:43 pm
by KCStudly
I don't think you need to be all that specific.

The big thing is you don't want to fully crush the seal like a gasket. So for example, using Grant's hatch seal at .400 tall x .625 wide free height, you only want to compress it to about 2/3 it's original height, or to about 1/4 inch high. The sides of the seal will bulge out, so you need to leave some width in the rabbet for that. IIRC, when I checked mine that seal went to about 7/8 inch wide when fully compressed. I'd have to double check that to be sure.

So, IMO, you want the hinge side of the joint to come together face to face hard (to take the wall load) but you want to leave a space about 1x 1/4 inch for the seal. That space could be divided top and bottom, or could be just on the bottom with the seal adhered to the flat underside of the upper piece. I suspect that the zig-zag joint in the WW design is there to both key the walls together for strength, and to add a labyrinth or cofferdam effect to help keep water out.

Grant's seal does come with a self-adhesive backing, and when I spoke with him he said he doesn't see any problem with squeezing it down a lot further (it will go to about 1/16 inch), but the seal manufacturer's tech info that I have found say that 1/3 to 1/2 free height is the rule of thumb for long seal life.

I don't have good drawing software here at home, or I would do a scale sketch of what I am envisioning.

Re: Weather stripping

PostPosted: Tue Apr 21, 2015 7:20 pm
by OP827
I think I can picture what you described, KC. I also do not have a software handy at the moment to do a sketch. I start to like the idea of having grooves up and down and the seal located inside. This should also help with the parts holding together and avoid some extra rubbing and movement during transportation. I probably will need to cut thin groves or weep holes that are perpendicular to seal lower groove so that when moisture is collected in the lower grove then it has a way to drain, similar to windows weep holes. For that reason I would probably preffer to fix the seal on the upper part. Is that the idea, what do you think?

Re: Weather stripping

PostPosted: Tue Apr 21, 2015 8:14 pm
by KCStudly
I think we are talking about the same thing. I'm not sure that I would bother with the weep holes, unless I am misunderstanding again. By keeping the seal on the top when the wall is lowered the water would no longer be trapped; and despite the fact that there is no pitch, I would think that it would dry okay.

I guess that is one of the challenges to such a (relatively) complicated design.

My $.02... and this is purely intended to imply that you are a braver man than I... I would be much more likely to build a lifting roof with a cofferdam, like Sharon's MyAway, but would probably stick with soft sides like Mike Young's build. In fact, if I do ever build a second it might even be a trolley top slouchy, or even full standy. But then again, towing efficiency isn't my biggest concern.