[Rhodes22-list] Deck joint repair - NP 1 sealant
The Rhodes 22 Email List
rhodes22-list at rhodes22.org
Wed Dec 10 14:17:33 EST 2014
One nice thing about 3M 5200 is that it is water soluble for about an hour
after it comes out of the tube. That makes it possible to clean up without
using aromatics and it helps preserve the integrity of the seal.
Rick
On Wed, Dec 10, 2014 at 1:43 PM, The Rhodes 22 Email List <
rhodes22-list at rhodes22.org> wrote:
> For those who want more information on the sealant Rummy used for his deck
> hull join now called Master Seal NP-1 (formerly Sonolastic NP 1) the spec
> sheet is available here:
>
> http://assets.master-builders-solutions.basf.com/Shared%20Documents/EB%20Con
>
> struction%20Chemcials%20-%20US/Construction%20Systems/Data%20Guides/MasterSe
> al/basf-masterseal-np-1-tds.pdf .
>
> The sealant seems to have all of the properties that would be advisable for
> such an application such as high flexibility, can be immersed in water,
> tenacious, sticks to anything and is available in a range of colours such
> as
> off white. It appears to be available at Home Depot and is much cheaper
> than
> the traditional marine sealants.
>
> Nice find Rummy.
>
> Graham
>
>
>
> -----Original Message-----
> From: rhodes22-list-bounces at rhodes22.org
> [mailto:rhodes22-list-bounces at rhodes22.org] On Behalf Of The Rhodes 22
> Email
> List
> Sent: December-10-14 7:27 AM
> To: rhodes22-list at rhodes22.org
> Subject: Re: [Rhodes22-list] Deck joint repair.
>
> Graham,
> The newer boats all use a plastic rub rail. Aluminum was scrapped years
> ago.
> NP1 sticks to anything it comes in contact with. It is used in roofing
> because it seals during expansion and contraction events. It also has a 15
> year direct exposure guarantee from the manufacturer. You are correct in
> that you don't want to apply more than you can install the pop rivets and
> tighten within an hour or so. It takes several days to fully cure, but
> becomes water tight after skinning over. It never fully "hardens".
> I did this procedure approximately fifteen years ago on Rumrunner and to
> this day it's still water tight.
>
> Rummy
>
>
> In a message dated 12/9/2014 11:00:25 A.M. Eastern Standard Time,
> rhodes22-list at rhodes22.org writes:
>
> As expected, Rummy's instructions are spot on excellent. I might add a
> few
> additional bits that he does not mention and Rummy can correct me if I am
> wrong.
>
> On my boat (1976) not all of the rivets came all the way through to the
> aluminium rub rail. To remove all of the rivets I had to remove the
> aluminium rail and I was unable to do that without destroying it as any
> bends that you put into the rail cannot be straightened. So plan on
> replacing the rub rail with a new one.
>
> The sealant you decide to use might determine how much you should do at
> one
> time. I am not familiar with the sealant Rummy uses but as it is intended
> for roofs, I suspect it stays very soft. Perhaps Rummy will advise what
> happens to the sealant he uses as it cures. But if you use a sealant that
> hardens up when it cures such as any of the marine sealants you will want
> to close the gap with rivets or bolts before the sealant cures. If you
> seal
> all the way around the boat and then start adding the rivets the sealant
> will cure before you will be able to compress the join.
>
> You will no doubt find that everyone has strong and differing opinions
> about what sealant to use and in the end you will need to go with your
> best
> judgement. Obviously you want a top quality sealant that will last
> indefinitely. You will also probably want one that has excellent expansion
> capabilities. As the deck and hull expands and shrinks and also flexes, it
> is important that the sealant has the ability to tolerate that change.
> Even
> sealant that has excellent elasticity will not work if it is applied too
> thin. Boat windows made of Plexiglas and attached to the exterior without
> hardware use a combination of special thick double-sided tape and high
> flex
> sealant - usually Dow-Corning 795. The tape is extremely adhesive but also
> maintains about a 1/8" gap between the window and the cabin side that
> allows the sealant to be thick enough to work properly. The 795 sealant is
> extremely flexible but also extremely adhesive.
>
> The main issue in the case of the hull deck join, in my opinion, is not so
> much adhesion, as the rivets will hold the boat together, but rather to
> maintain a good permanent and flexible seal. You might consider using
> butyl
> for this (the form that comes in a tube) but because it would add nothing
> to the strength of the join I would double up on the rivets/bolts.
>
> One argument that might favour bolts over rivets is that you can tighten
> the bolts as needed while rivets apply maximum pressure. If you want to
> make sure that the sealant is not all squeezed out of the join, bolts
> would
> give you that degree of control. With butyl, that should be less of a
> concern.
> There is a lot (too much) of information on the net about the pros and
> cons
> of various sealants. I would be interested to know which sealant Stan
> would
> recommend.
>
> Widen the gap with wooden wedges/shims ahead of where you are injecting
> the
> sealant to ensure that the sealant is injected well into the gap. Put the
> shims in first as needed and then remove each as you reach that point with
> the sealant. That will allow you to get more sealant into the join and the
> removal of the shim will squeeze the sealant immediately while it is still
> uncured.
>
> Another thing I would worry about is removing all of the rivets at once.
> The
> hull is very thin and very flexible at the top and I would worry about the
> whole thing changing shape one all of the rivets and sealant has been
> removed. Assuming that the boat is on its trailer when you do the job and
> knowing that the trailer applies uneven pressure to the hull, I would not
> want to find that the boat hull and deck became misaligned. That might not
> happen but at the same time you can avoid the risk by doing sections of
> about 8' at a time. Remove the rivets in one section only after the
> previous
> section has been sealed and riveted/bolted. Alternatively, replace some of
> the rivets (say every 4') temporarily with bolts that can be easily
> removed
> as you work your way around the boat.
>
> I would definitely add more rivets or bolts to those presently on the boat
> especially around the fore deck. I think that the waves on the bow work
> the
> hull-deck join as the hull is very flexible in comparison to the rigid
> deck
> and that is where the sealant can/will break. Certainly on my boat it was
> only at the front section that I had trouble with leaks.
>
> Finally, if you use rivets, I would definitely use washers with them.
>
> Good luck
>
> Graham
>
>
> -----Original Message-----
> From: rhodes22-list-bounces at rhodes22.org
> [mailto:rhodes22-list-bounces at rhodes22.org] On Behalf Of The Rhodes 22
> Email List
> Sent: December-09-14 6:04 AM
> To: rhodes22-list at rhodes22.org
> Subject: Re: [Rhodes22-list] Deck joint repair.
>
> Chuy,
> I'm a little short on time, but I will try to detail the procedure the
> best
> I can.
> Remove the rubber insert from the rub rail. In most cases it has
> deteriorated enough that you will want to replace it with new. Having
> removed the insert you have found the pop rivets which you will have to
> drill out in order to remove them. Most of the rivet will fall into the
> interior of the boat and you will continue to find them for several years.
> After drilling all the rivets out you will clean the deck joint (area
> between the two surfaces) with something small enough to remove the
> hardened and worthless caulking.
> The cleaner the joint is, the better. I recommend and used on my boat a
> one
> part polyurethane sealant called NP1. It is manufactured by a company
> called Sonolastic and is primarily used in roofing applications so it has
> great adherence and weathering properties. It will stick to anything and
> can be easily found through Google.
> Now comes the really important part, filling the voids in the seam. Using
> a
> caulking gun, you will squeeze the trigger as you push the gun forward,
> driving the caulk into the seam. This is reverse as to how you normally
> apply caulk, but you want to fill all the voids. Once the seam has been
> sealed, replace the rivets which you have purchased from an industrial
> nuts and bolts supply house and attach the rub rail. Count the holes
> before going and add 10% just because. Do not try to find them at a
> hardware store, they don't have them. I used a hand operated pop rivet
> gun, but I would recommend purchasing a pneumatic or electric gun to save
> wear and tear on your hands and arms.
> Simply sealing the top and bottom edge of the rub rail doesn't do squat
> for
> stopping water infiltration and besides, it looks crappy.
> Good luck and if you have any further questions don't hesitate to ask.
>
> Rummy
>
>
> In a message dated 12/8/2014 12:52:48 P.M. Eastern Standard Time,
> rhodes22-list at rhodes22.org writes:
>
> Rummy,
> Searched list but did not find any material on your deck join repair. I
> would appreciate if you could repost.
>
> Chuy
>
>
> ---- The Rhodes 22 Email List <rhodes22-list at rhodes22.org> wrote:
> > Chuy,
> > If you search the list archives you will find a post from me
> > detailing
> the
> > easy resealing of the deck joint. If you can't find it, let me know
> > and
> I
> > will repost to the list. It's a not to difficult repair, but if not
> done
> > correctly, you will find yourself doing it all over again.
> >
> > Rummy
> > __________________________________________________
> > To subscribe/unsubscribe go to
> http://www.rhodes22.org/mailman/listinfo/rhodes22-list
> >
> > For the list Charter and help with using the mailing list and
> > archives
> go to http://www.rhodes22.org/list
> > __________________________________________________
>
> __________________________________________________
> To subscribe/unsubscribe go to
> http://www.rhodes22.org/mailman/listinfo/rhodes22-list
>
> For the list Charter and help with using the mailing list and archives
> go
> to http://www.rhodes22.org/list
> __________________________________________________
>
> __________________________________________________
> To subscribe/unsubscribe go to
> http://www.rhodes22.org/mailman/listinfo/rhodes22-list
>
> For the list Charter and help with using the mailing list and archives go
> to http://www.rhodes22.org/list
> __________________________________________________
>
> __________________________________________________
> To subscribe/unsubscribe go to
> http://www.rhodes22.org/mailman/listinfo/rhodes22-list
>
> For the list Charter and help with using the mailing list and archives go
> to http://www.rhodes22.org/list
> __________________________________________________
>
> __________________________________________________
> To subscribe/unsubscribe go to
> http://www.rhodes22.org/mailman/listinfo/rhodes22-list
>
> For the list Charter and help with using the mailing list and archives go
> to
> http://www.rhodes22.org/list
> __________________________________________________
>
> __________________________________________________
> To subscribe/unsubscribe go to
> http://www.rhodes22.org/mailman/listinfo/rhodes22-list
>
> For the list Charter and help with using the mailing list and archives go
> to http://www.rhodes22.org/list
> __________________________________________________
>
More information about the Rhodes22-list
mailing list