Attaching covers etc. to hatch cover lens with industrial Velcro

[thinwater]

Anyone ever try attaching anything directly to the lens with industrial removable fasteners (3M Dual Lock is what I am actually considering--the stuff commonly used to attach speed-pass transmitters to windshields)?

My concern is that the pull required to separate the fasteners (remove the cover) represents a pretty good outward pull on the lens. How much suction force can they safely manage? Given those I see used as escape hatches in cats, I gather quite a bit.

[colemj]

If removing is a concern, slipping a screwdriver blade or other flat thing between the mating locks separates them easily.

Mark

[thinwater]

Very true.

The interesting thing about Dual Lock vs. Velcro is the way it snaps into place with a click and parts in a similar manner. Great for attaching fairly rigid panels and such. Very unlike Velco on a coat sleeve.

A plastic blade would be the thing (no scratching). There will be ~ 1/8" gap.

Originally Posted by colemj

If removing is a concern, slipping a screwdriver blade or other flat thing between the mating locks separates them easily.

Mark

[J Clark H356]

I use 3M Dual lock all over our boat. We attach pictures, hold open our companionway doors, lamp bases, holds my peekaboo shades to my overhead hatches, Globalstar phone near window. I've used it for 13 years and when I remove it, it leaves no residue or marks on the teak, fiberglass or anything else. Highly recommend it over Velcro.


Sent from my iPad using Cruisers Sailing Forum

[thinwater]

Originally Posted by J Clark H356

I use 3M Dual lock all over our boat. We attach pictures, hold open our companionway doors, lamp bases, holds my peekaboo shades to my overhead hatches, Globalstar phone near window. I've used it for 13 years and when I remove it, it leaves no residue or marks on the teak, fiberglass or anything else. Highly recommend it over Velcro.


Sent from my iPad using Cruisers Sailing Forum

The only down side I have found is that if it gets a grip on certain materials (some carpets, some bug netting) it will literally tear them apart getting it separated. I was going to use it on a large screen, and that was a disaster.

After years of use, how do you remove it? Simple work something under the corner and heave?

[J Clark H356]

It does snag some items like a terry cloth rag. When I remove it, I just get it started with a thin blade and slowly pry it off. Usually after getting it started, I can pull it off, but it has a good grip.


Sent from my iPad using Cruisers Sailing Forum

[Dave22q]

I would have two concerns. Would frequent sharp pulls on the lens tend to pressure the gasket causing an eventual adhesion failure and leaks? They are not designed to resist direct pressure. I would also want to make very sure that the glue used to apply the Velcro to the lens would not interact negatively with the lens and would be removable. If you could attach your Velcro to the metal casing rather then the lens, I see no downside.

[ramblinrod]

IMHO, "Hook and Loop" (trade name Velcro) has no business on a boat anywhere. The hook portion attaches to things you don't want it to, catches on and ruins clothing, etc. Then of course, it loads up with all kinds of fuzz and threads that need to be cleaned out. Just a nuisance. I've seen some boats with Hook and Loop plastered all over the companionway and forward hatch, just waiting to grab hold of you as you enter or exit. Even if one puts the loop portion in these locations, it is ugly and totally unnecessary. There are far better solutions for attaching things to a boat.

[a64pilot]

I had covers made that use a draw string to keep them on, the draw string will go slightly under the lip of the hatch, if you make covers insulate them well, you wouldn't believe how much heat a well insulated cover keeps out of the boat.

[ranger58sb]

Originally Posted by thinwater

Anyone ever try attaching anything directly to the lens with industrial removable fasteners (3M Dual Lock is what I am actually considering--the stuff commonly used to attach speed-pass transmitters to windshields)?

What are you trying to accomplish? Keep stuff off the lens exterior? Keep light out? Insulate for temperature? Or...?

-Chris

[thinwater]

Dave22q. Yes, the outward pull is the question. Unfortunately, on the hatches I'm looking at the metal frame slopes away too far.As for interaction, the adhesive has proven safe with polycarbonate and acrylic.

ramblinrod. Perhaps, but that sort of broad statement reminds me of declarations that silicone has no place on a boat. Additionally, Dual Look is not hook and loop in the strict sense; the protrusions are the same on both sides and resemble mushrooms. We have discussed that it does grab fabric and would certainly not be used around a companionway.

ranger42c. Fair question. Actually, it was more an exploration than something I am planning. However, winter insulation is not a concern, since these hatches are fitted with internal double glazing. UV protection would be nice, as would protection from foot traffic and impact. I dislike tie-on canvas covers; perhaps this is only because of bad experiences with some that would not stay on and interfered with hatch sealing.

The Outland Hatch Covers attach with a different sort of fastener and seem to work very well.

----

Dual lock is quite different from Velcro in how it functions. The peal force is not very high, once an edge is started, but the pull off strength is considerable. When attaching, the object sort of snaps into place and requires a light prying in many cases to remove. Unlike Velcro, it does not tend to creep loose, which is why it is useful for speed passes. Different from Velcro, it is for things that you would like to be removable, but not often.

[a64pilot]

I have "shades" that go inside of the port lights that use what I believe is this duraloc from your description, and it works very well, I don't see why it wouldn't work well on the outside, you may only need four .5" "dots" of the stuff, one on each corner, it holds a lot tighter than Velcro and without all the wiggle Velcro has.

[svbeyond]

Put the dual loc on the aluminum and sewn to cover. Works great until native adhesive backing on tape fails. Tried JB weld-worked but also failed eventually. Sold boat so DK yet how next (boat) attempt goes - think I'll call 3M; maybe try 3M VHB(?) industrial tape. Also dinghy chaps w/dual loc on sewn to fabric but soft velcro glued to tube works.