bow pulpit - second video

[BobCT]

This has taken a lot of time but it just needs finish and then reinstall. Hopefully I'll get it back on before it gets too cold. Still in the 50's up here.

I'll post the final one when it's all done.

Bob

http://www.youtube.com/watch?v=Rs3oSagW ... e=youtu.be

[RWS]

Thank you O B -Wan for your instrustional visdeo into the mysteries of the pulpit.

Would it be possible to flip it upside down and drill a large number of holes into the remainaing wet balsa area for thwe purpose of injecting either West system product or GitRot into the balsa?

I really like the idea of using starboard under the teak but what will adhere to it? How to keep water from getting under it and also the potential for water getting between the teak layer and the starboard?

THANKS !

RWS

[larryeddington]

Let me give a suggestion about de-watering (Moisture) anything of reasonable size. If one can make ( I have given some serious thought to this) a container out of some pressure vessel, that is sizeable enough to contain the damp object, one can seal the object within and pull a good vacuum and at room temperature the moisture will boil off leaving the object dry. This can be done without damaging heating.

Thoughts anyone, I realize some thing are just too big. I have thought about using an old pressure tank to make such a device.

Thoughts?

[Big D]

Do a Google search on vacuum drying boats or hulls to remove moisture. This is the best way to get rid of the moisture without opening the unit. Works on the principal of lowering the boiling point of water by lowering the pressure and subjecting the area to a vacuum. Doesn't take much to accomplish this. You could make water boil and turn to vapour at zero degrees! As it boils, the vapour is extracted by the pump. You could have that thing dry or at acceptable moisture levels in hours or a few days depending on content. Done all the time in shops for drying out soaked hull cores prior to epoxy treatment or in treating a blister problem, etc. A little research on-line and a good vacuum pump is pretty much all you need, except for some plastic, tape, maybe putty, etc. Check it out. It's hi tech but a simple principle. This is one of those things that falls under the "don't work hard work smart" category

[Big D]

Ooops, sorry Larry. Had a reply on the go for a while...little guy took me away. You're absolutely correct; best method to use here. No need for a pressure vessel, just cover in plastic. And nothing is too big for this method, you can simply do sections at a time.

[aaronbocknek]

This has taken a lot of time but it just needs finish and then reinstall. Hopefully I'll get it back on before it gets too cold. Still in the 50's up here.

I'll post the final one when it's all done.

Bob

http://www.youtube.com/watch?v=Rs3oSagW ... e=youtu.be

wow bob,cannot wait to see the finished product.
also responded to the youtube link.
aaron

[larryeddington]

Vacuum is what we use to dehydrate refrigeration systems. I have experimented with an improvised small vacuum can and it worked perfectly. BTW I would not hesitate to try and de water an electronic device. Rinse it out good with fresh water then vacuum treat.

A word of caution, the vacuum chamber must be strong and no dents, remember you can put up to 14.7 lbs per square inch on every inch of the surface pushing in. If the vacuum chamber should fail it will fold inward and may crush what you are trying to dry.

Sealed in plastic will work and elimanate the crush potential. Good way to laminate etc, vacuum can be the perfect clamp.

[Big D]

Larry, if you're in refridgeration, you'll have access to what I've used in the past; a simple field refridgeration vacuum pump. I don't have one anymore but have access to one from a friend still in the business. The hardest part is creating a good attachment point to the bag, and even that isn't so bad. Like you said, it pretty much seals itself. Check out the sight below; they manufacture specialized equipment but really all you need is a thin plastic sheet, I used putty to secure the edges, turn the vacuum on and walk away.

http://www.hotvac.com/

[prowlersfish]

Great info on the vacum

[larryeddington]

Yep, I was in refrigeration and still have my equipment. I have run my vacuum pump for over 24 hours with no problem. Sometime on larger systems running overnight is a good thing checking vacuum with a vacuum gauge that measures in microns left inside. Not necessary for drying things out, but I would not be afraid of extensive running on a good vacuum pump.

You are correct the connection is the weakest point, holding a vacuum is much harder than holding in pressure as a "perfect vacuum" is a full 30 inches of mercury which cannot be accomplished on earth, but you can get close. Small leaks show up easily as max pressure trying to get in is 14.7 lbs per square inch. While compressing air (pressure trying to get out) can be way higher, therefore the volume of compressed air is far higher and will not show up on guages as easily.

Hope I did not complicate this. If you can seal it somehow the vacuum will dry anything out without heat, though any heat, heat lamps etc will speed it up, but not necessary.

BigD link does not work.

[Big D]

Try the link now

[larryeddington]

Sorry Big D no link.

[Big D]

I meant the link in previous post Here it is again.

http://www.hotvac.com/

Look at this page and scroll until you see the picture with the plastic and putty frame, that's what I'm talking about. Can be any size area.

http://www.boardlady.com/waterextraction.htm

[larryeddington]

any positive seal would work, as was said hard to make the connection.

In a perfect world IMO the best would be a pressure cylinder large enough to place the whole piece or the whole boat (I realize cost would prohibit accomodating that big of container). But if so the very best way would be to vactuum dry the whole boat and repressurized to atmosphere with dry nitrogen. All moisture would be extracted from anywhere inside the chamber which would include all parts of boat.


If a perfect world existed! Oh well pipe dreams.

[gettaway]

Can you buy a vacum bag kit from West system?