Insulation

[bottle]

Sprayfoam versus 'Thinsulate' by 3M.

 

I have to decide which one to use, have had a look at both, your thoughts opinions and any experience would be appreciated.

 

I have heard but cannot confirm that sprayfoam has been known to 'fall off', become unstuck.

 

Thank you in anticipation.

[stuart]

I've used the sheet thinsulate type material on my boat.

 

It was easy to work with and apply. Just wedges inbetween the various bits of metal and wood on the cabin sides.

 

You still need some other method of covering and remaining visible metal (normally on the roof strengthing bars) to avoid cold spots/bridges where condensation can form. Very thin insulation sheets/rolls can be used for this or aersol spray foam.

 

Happy with the performance of the insulation as well. Its 1" on cabin sides and 2" below.

 

Edited May 31, 2005 by stuart

[John Orentas]

Though out of fashion for some reason now I have always used expanded polystyrene sheet, it is easy to use and it's cheap to buy.

This cold spot problem only occurs when the lining material is in direct contact with steelwork, as long as everything is battened out properly there will be no problems.

There have been questions about flammability but the stuff is approved and used extensively in the building industry.

[bottle]

Thank you to both of you

[ChrisPy]

polyurethane foam is difficult to maintain a consistent thickness, and is one hell of a mess to trim off back to the level of the battening. It took us 20 manhours on a 57ft widebeam, using a B&D Scorpion saw, paint scrapers and some breadknives.

 

having said that, I wouldn't do it any other way. The big advantage is that it eliminates any possibility of condensation on the cold inner surface of the cabin sides and ceiling, at a stroke. So I expect my boat to be bone dry above the bilge, unless the seals around the windows or vents leak. It also deadens the sound, because it adheres and prevents 'drumming'.

 

if there is a serious deficiency in thickness at any point (the common problem with a poorly supervised subcontractor) you can always beef up the thickness by stuffing some rockwool behind the panels. I thought about this. But I stayed cool inside the boat even when I couldn't crawl on the roof because of the hot sun (I was burning my knees through a pair of jeans and a pair of overalls as I crawled around fixing the mushrooms onto bare steel). I decided that the varying thickness of foam (from half an inch up to two inches on the ceiling for example) was adequate to the task.

 

does it fall off? I don't think so. If the steel surface is sound it should last forever. If you doubt that look up Balcotan glue, which is now a wooden boatbuilding standard and uses the same technology. Polyurethane is even tolerant of damp conditions during application, because it needs the water in the air or on the surface to help it to cure.

[DHutch]

EmilyAnne also uses expanded polystyrene, but 15years ago there was a lot less of this fancy "sheet thinsulate" type insulation, and everyone used EPS, so weather it sensable to use that no, i dont know.

- Dont forget you can let PVC cable touch the styrene. (you need to run it in trunking, or use special cable)

 

 

Daniel

[Gary Peacock]

Having tried most things over the years spray foam wins hands down if you can afford it. No need to prime the interior, 100% coverage, prevents drumming, no condensation problems below water line, no condensation problems on bow thruster tube, if you get the water tank done that wont condensate either and it's very effective insulation too.

 

We offer to fit 3m keep your hands and feet warm stuff so why don't we try and think of another use for it stuff too! I don't think for the extra cost it would do all the above quite so well.

 

If you spend time on preparation and use an experienced sprayer plus make it clear what you want them to do the work after should be minimal.

 

Gary

[bottle]

Hi

 

Gary, its not the cost so much as I want the best that I can afford, its to do with the life and effectiveness of the material i.e the thermal and sound deadening quality for the same thickness.

 

The boat will be my home for the forseeable future as I do not plan to buy another one.

[ChrisPy]

Hi

 

Gary, its not the cost so much as I want the best that I can afford, its to do with the life and effectiveness of the material i.e the thermal and sound deadening quality for the same thickness.

 

The boat will be my home for the forseeable future as I do not plan to buy another one.

21287[/snapback]

Hey - go for spray foam - it's got to be worth the extra cost.

 

if I was tring to save a bob or two it would not be on the insulation. out of sight, out of mind, no problems for the life of the boat.

[Gary Peacock]

Hi

 

Gary, its not the cost so much as I want the best that I can afford, its to do with the life and effectiveness of the material i.e the thermal and sound deadening quality for the same thickness.

 

The boat will be my home for the forseeable future as I do not plan to buy another one.

21287[/snapback]

 

In that case I would go for spray foam I have all the details of Thinsulate and have seen the power point presentation I had the rep a bit tied up when I put some questions to him and it all smacked of a bit of clever marketing rather than true experience in our corner of the industry. (It is very popular in conjunction with fibre glass though) To have a go with it on a DIY basis and to spend a lot of time bonding it to the steel after you have primed it with something first would probably be very effective, however it does not have the rigidity of foam so would not help to tie the battening in place the same way or reduce vibration in the steel either.

 

Saying all that we have agreed to install it, if customers want it they can have it the insulation values and sound proofing figures are very impressive.

 

 

Gary

[bottle]

Hey - go for spray foam - it's got to be worth the extra cost. 

 

if I was tring to save a bob or two it would not be on the insulation.  out of sight, out of mind, no problems for the life of the boat.

21290[/snapback]

 

Thanks Chris

 

As far as I know the 'thinsulate' is more expensive, but I cannot decide which one to have, the best is not always the most costly.

 

My approach to this is I want the best, cost is a minor factor.

[stuart]

To follow my comments earlier about using insulation sheets - if I were to do another boat in the future (and I might!!) I would have it spray foamed rather than use the sheets again!!

 

Its just easier to pay someone else to do the work for you. I grossly under estimated the time it takes to put the insulation sheets up and cut them to size - however my time is free

[bottle]

<SNIP>

 

Saying all that we have agreed to install it, if customers want it they can have it the insulation values and sound proofing figures are very impressive.

Gary

21291[/snapback]

 

Thanks Gary

 

It was the figures that I do not understand, the rigidity etc I had not thought of.

[bottle]

Well I have made a decision: It will be sprayfoam it may not have the best 'figures' but it is a tried and tested solution in this particular situation.

 

 

I thank you all

[david and julie]

I have just started removing the excess sprayfoam off my sailaway(pictures soon) and it was made far easier by applying duct tape onto the battens before spraying.

 

Although this is dearer than masking tape it is much stronger and therefore stays in one piece when you remove it. The tape pulls off in long lengths without snapping, saving both time and effort.

[Gary Stacey]

The only problem with sprayfoam is if you need to do any welding to the exterior it has to be removed from the inside first

 

Gary