Spray Foam or Styrofoam

Guest · Post by **Guest** » Wed Oct 20, 2004 3:24 pm

First I will introduce myself,my name is Don.My Wife,Patti,and I are new Mac owners,new "M" April,2004 Blue Hull # 475.We live in DeLand,Fl.app 20 miles west of Daytona Beach. I have been visiting this site for awhile,and joined the other day.I think this is a great site,the Questions and the Answers! Thank you all. My question is,after digging out some of the styrofoam in the mast to run my V.H.F. coax,can I redo it with that "Spray Foam" available at the Home Stores?

Thank You

Paul S · Post by **Paul S** » Wed Oct 20, 2004 6:04 pm

DonandPatti wrote: First I will introduce myself,my name is Don.My Wife,Patti,and I are new Mac owners,new "M" April,2004 Blue Hull # 475.We live in DeLand,Fl.app 20 miles west of Daytona Beach. I have been visiting this site for awhile,and joined the other day.I think this is a great site,the Questions and the Answers! Thank you all. My question is,after digging out some of the styrofoam in the mast to run my V.H.F. coax,can I redo it with that "Spray Foam" available at the Home Stores? Thank You

There is foam in at least 3 spots along the mast..not just the end.

I have not got around to putting foam back in. Not sure if it is better or not to have the foam in there or to let the water drain if it goes over. I was going to use great stuff foam to fill in the voids

Paul

Chip Hindes · Post by **Chip Hindes** » Wed Oct 20, 2004 8:56 pm

"Great Stuff" or any other self expanding foam should work fine for replacing the missing foam. The point is that the foam seals the mast and keeps the water out, so the floatation is provided not by the foam but by the air trapped in the mast.

It should work for us X owners as well.

Paul S · Post by **Paul S** » Wed Oct 20, 2004 9:47 pm

Chip Hindes wrote:"Great Stuff" or any other self expanding foam should work fine for replacing the missing foam. The point is that the foam seals the mast and keeps the water out, so the floatation is provided not by the foam but by the air trapped in the mast.

It should work for us X owners as well.

That would be fine..but there are holes in the mast between each of the areas of foam. kind of defeats the purpose of 2 air compartments in the mast. Not sure why all the holes were not filled up.

Not sure if it was knocked down and filled with water, water would get in, not get out quickly. I never refilled my mast after it was done. I probably should. It is on my list

Paul

Post by **kmclemore** » Thu Oct 21, 2004 4:56 am

Chip Hindes wrote:"Great Stuff" or any other self expanding foam should work fine for replacing the missing foam....

Just a note of caution - there are two types of foam being sold. One is laytex based and the other is urethane based. I didn't realise this myself until I bought some and used it to fill the tubes that go through the cockpit sole under the pedestal (where the steering & motor cables go). When I sprayed the stuff it didn't quite smell like the stuff I was used to, and it had a smoother consistency and white color like whipped cream instead of the usual coarse texture and yellow color I was accustomed to.... well, let me tell you, it was a HUGE mistake.... the damned stuff is water soluable and does NOT prevent leaks... a week later it rained and I had that garbage running down all over inside the boat, even though it had been drying for days... I ended up having to rip it all out and replace it with true urethane foam.. a total mess.

So my advice is to check the cleanup instructions on the back of the can... if the foam cleans up with water, don't buy/use it.

Chip Hindes · Post by **Chip Hindes** » Thu Oct 21, 2004 7:04 am

Paul wrote:That would be fine..but there are holes in the mast between each of the areas of foam.

That would certainly defeat the purpose, but the real question is, what holes? I assumed (silly me) that any major penetrations, such as the forestay hound and the babystay bolt, were also sealed. As I recall without inspecting my X, there are no "empty" holes through my mast; each has at least a fairly close fitting bolt through it. Is this not the case? The other stuff: various blocks, cleats, masthead light, etc, are not gasketed, but it would take quite a long time underwater for any serious water to leak through those.

I believe it's likely that the primary purpose of the sealed mast is only to assist in bringing the boat onto its side quickly in the event of a roll, where the inherent stability provided by the full ballast tank can take over to pull the boat upright and get the mast out of the water before it has a chance to fill. So, it doesn't have to seal forever, just long enough to get itself back out of the water; should be only a matter of seconds.

Interesting and semi-morbid question: anybody know if, when the boat is on its side with the cabin and cockpit full of water, is the mast fully submerged?

Crocus26X · Post by **Crocus26X** » Sat Oct 30, 2004 9:19 pm

Fun with foam-NOT.
I attempted to fill my 26X's mast with "Great Stuff" and am happy to share my learnings.
My reasons for doing that was to add bouyancy and to stop any wires inside mast from moving. I had added a VHF antenna cable and was concerned that it might rattle. Before foaming I ran a lightweight 3/4" plastic tube for future wiring from top to bottom. My plan was to completely fill the mast to minimize water being trapped. While capsizing is one way to fill the mast I was mostly concerned with water from the sky entering the many small openings in the mast and not draining. Water ballast gone wrong! I attached a length of vinyl tubing to the spray can nozzle long enough to reach half way between the various openings in the mast. At this point I would advise that a little practice run would be a good idea. Take a piece of pipe of about the same inside section as the mast and practice filling it BEFORE starting on the mast. I fed the tube in, started the injection and expected that as the foam expanded I would see it ooze out of the numerous holes as I withdrew the tube ahead of the filling. Things didn't go quite as expected and it seemed to take much more foam than I expected to fill the cavity and very little came out of the openings. I really don't know how sucessful I was in completely filling the mast. I still think it was a good idea but next time I would practice first.

Duane Dunn, Allegro · Sat Oct 30, 2004 10:14 pm

Did you use the true expanding variety of foam? There are different kinds out there now. Some have very low expansion charateristics so they don't warp windows and things when you fill around them.

Crocus26X · Post by **Crocus26X** » Sun Oct 31, 2004 8:54 pm

Duane Dunn, Allegro wrote:Did you use the true expanding variety of foam? There are different kinds out there now. Some have very low expansion charateristics so they don't warp windows and things when you fill around them.

I used the regular, full expanding, formulation. I suspect that expansion gets restricted by the mast and the already expanded foam inside it. By practicing with the mast mock-up the rate of injection and the volume of foam could be monitored.

Dimitri-2000X-Tampa · Post by **Dimitri-2000X-Tampa** » Mon Nov 01, 2004 7:40 am

Agree with Chip this time.

Anyone who windsurfs a lot will tell you that you have to get that mast out of the water quick before it fills with water.

I think that just filling the end with foam would be sufficient and this is what I plan to do one of these days.

Jeff S · Post by **Jeff S** » Mon Nov 01, 2004 2:46 pm

I concur with Chip and Dmitri on this, and I plan to foam the top part of my mast when I finish adding a new VHF antenna and Anchor light....but does anyone know where to get some type of mast cap for the X? I searched and apparently at some point in X production they got rid of the mast cap and with the M they reintroduced it. I want something on which to mount the Anchor light and antenna. Any suggestions? Experiences?

Jeff S

Guest · Post by **Guest** » Mon Nov 01, 2004 3:26 pm

Thank you all for your answers and advice

Thank you Chip , I didn't think that it would be the "Air" trapped inside,thats great. Thank you Paul S , yes I did know there is more than one {1} place, thanks anyway.KMClemore,i'm sorry to hear about your problem with the "Latex" version

,I guess there wasn't enough air to dry it? What ever the reason, i'm glad you were able to redo it. Yes I did use "Great Stuff", I also pulled a double wire through with my coax. At the very top of the mast , I slipped a piece of 1/2" x 8" P V C over the wire and folded the wire several times , then stuffed it in the P V C ,so when i'm ready to add my anchor light , the wire will be easy to pull out , yet the mast is sealed. Again, thank you all for your help . Happy Sailing Don

jmdefino · Post by **jmdefino** » Mon Nov 01, 2004 9:45 pm

I took a slightly different approach. I purchased some of the gray foam pipe insulators from Home Depot. I slipped as many of these as I could into the top of the mast. I then made a cap out of some starboard and screwed it in the top.
Adds flotation and further quiets the wiring.

norbert · Post by **norbert** » Tue Nov 02, 2004 1:50 pm

i mounted a square piece of aluminium flat on the mast top. it has about 10x25cm (4x10 inch), covers the mast and makes a little "tail" behind it. i mounted my 3-color- and anchor light straight over the mast and the windex a little bit more aft. the mast cover prevents rain and dirt from pouring down the mast and the birds from building their nest inside (a had this one time in the spring!).

Dan B · Post by **Dan B** » Thu Nov 04, 2004 10:55 am

IF the purpose behind the foam was primarily to stop wires from slapping around inside the mast - a simple way to handle it is to put zip ties along the wire every few feet with the tails facing opposite directions (and don't snip the excess tails.) The tails will help hold the wire away from the inside mast wall.

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