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Crayfish · 26-04-2013, 07:41

Those who want to do a good job and try to get rid of the hydrolysis products such as styrene and propylene glycol (apparently the culprits of osmosis) might try a homemade Hotvac. It's a tedious process as I've got only two heating mats but we are very happy with it and it works nicely (a total drying per square meter takes between 5 to 10 hours).

What's convenient about the custom made mats: The RAYCHEM self regulating heating cable sealed within the heat resistant RPDM rubber mats never exceeds (not even partly) the max. temperature of 110°C / 225°F. (When heating the laminate the temperature usually rises very quickly as soon as the laminate is dry and might thus damage the GRP.)

Regards
Volker

**minaret** · 26-04-2013, 07:57

People take note. This is an excellent home built system. Could be a real cash saver for someone with a wet boat. This is much more modern and well done than my attempts to help people make home made systems the old way, with electric heat blankets and a vacuum bag. Almost as nice as our ridiculously expensive Hotvac system.

**minaret** · 26-04-2013, 08:02

Volker, are you bagging the raychem wires between two sheets of rubber to make your matts? Adhesive? Do you bag in a vacuum fitting as well? What's the story with the space blanket?

Do you do your own peeling? I noticed on your blog you said you use Gelplane. I believe they are no longer selling units, and want to send a specialist instead. They tried to reclaim ours and we laughed at them.

Crayfish · 26-04-2013, 11:26

Quote:

Originally Posted by minaret

People take note. This is an excellent home built system. Could be a real cash saver for someone with a wet boat. This is much more modern and well done than my attempts to help people make home made systems the old way, with electric heat blankets and a vacuum bag. Almost as nice as our ridiculously expensive Hotvac system.

Thanks Minaret!

(And THANKS again for letting me have a look over your shoulder. Great great job you did on your Nauticat) http://www.cruisersforum.com/forums/...fit-95666.html

Volker

Crayfish · 26-04-2013, 12:15

Quote:

Originally Posted by minaret

Volker, are you bagging the raychem wires between two sheets of rubber to make your matts? Adhesive? Do you bag in a vacuum fitting as well? What's the story with the space blanket?

Do you do your own peeling? I noticed on your blog you said you use Gelplane. I believe they are no longer selling units, and want to send a specialist instead. They tried to reclaim ours and we laughed at them.

Yes, I sandwiched the Raychem wires in between two RPDM rubber sheets(3mm and 1mm) and vulcanised them. Very easy work. The sheets get very hot and close to their limits but they don't melt. Silicon matts would be better but much more expensive.

You simply punch a little hole in both sheets after they had been vulcanised and hand tighten the vacuum screw-connection. It's designed for it and absolutely tight.

I forgot to mention the heat resistant vacuum fleece which is to be put in between the matt and the hull, of course, and the special sealing around the matt. The Thomas vacuum pump is very small but quite effective.

As it was cold when I started hotvacing her I covered the matt with one of those emergency blankets which worked fine.

I really really enjoyed using the Gelplane as it is ridiculously easy. I'm a single man show as I'm not very rich. It took me two days to peel my Alden 44. Wonderful machine. The worst moments are those when you realise the size of your boat. It's a bit like being lost singlehanded in the midst of an ocean. But I'm quite good in not thinking so I use to forget about it.

They reclaimed your Gelplane? You are joking! Tell them we've got heaps of them here in Europe if they want to buy some

I rented a Gelplane for 250EUR M.u.H. von der Linden GmbH - GelPlane . ( would have payed twice the price.)

But you don't get Hotvacs.

Regards,
Volker

mischief · 30-09-2013, 14:44

Looks great. Where can you buy these supplies from?

**minaret** · 30-09-2013, 15:35

Quote:

Originally Posted by mischief

Looks great. Where can you buy these supplies from?

It's not like there's a one stop shopping source for everything. You are trying to replicate a complicated expensive machine. No one is going to do it for you, if you want to pursue this instead of paying someone a fortune, get out your research hat...

mischief · 01-10-2013, 14:56

I do realize this, and I can source a pump no problem and have spent a number of hours trying to source pads. Finding anything in Australia that's not widely accepted is difficult at best. Example I have imported 80% of my supplies. From caulk, butyl rubber, vents, chargers, solar etc etc. it's either non existent or up to 10x the price, usually 2-6 times the price is not unusual.

Since some items are common to utilize for a build like this in other countries doesn't mean they are easy to find via Internet.

With a lot of research for every project, it is time I spend not working on the boat. So I always appreciate a tip or two on a good place to buy items.

Often projects like this may have a blog or insight into the build, which also saves others mistakes and countless hours.

I'm not asking others to do it for me. After all this forum has always been a free exchange of ideas and information. So I was just asking that's all.

Cheers

**minaret** · 01-10-2013, 17:04

Quote:

Originally Posted by mischief

I do realize this, and I can source a pump no problem and have spent a number of hours trying to source pads. Finding anything in Australia that's not widely accepted is difficult at best. Example I have imported 80% of my supplies. From caulk, butyl rubber, vents, chargers, solar etc etc. it's either non existent or up to 10x the price, usually 2-6 times the price is not unusual.

Since some items are common to utilize for a build like this in other countries doesn't mean they are easy to find via Internet.

With a lot of research for every project, it is time I spend not working on the boat. So I always appreciate a tip or two on a good place to buy items.

Often projects like this may have a blog or insight into the build, which also saves others mistakes and countless hours.

I'm not asking others to do it for me. After all this forum has always been a free exchange of ideas and information. So I was just asking that's all.

Cheers

Of course, just sounded kinda, well, flippant. Always happy to help someone who has some idea what they are getting into.

Looks like Volker's link is dead, I believe this is the self regulating Raychem in question. Several similar options.

http://pentairthermal.com/Images/EN-...m432-26303.pdf

I have a link to Volker's blog somewhere, it's fairly detailed but in German of course. I'll see if I can find it.

Rubber matt-

Epdm Rubber Mat, Epdm Rubber Mat Products, Epdm Rubber Mat Suppliers and Manufacturers at Alibaba.com

Vulcanising the Raychem wire into the rubber matt should be easy. Then aquire pump and hose with the appropriate vacuum fittings and attach them to the matt. Make sure to use a quality laser thermometer to check all of each matt for hot spots. Shouldn't be a problem with Raychem wire, but you can't be too careful.

This is a doable project and the right thing to do for many boats. Could be a real money saver. If you try it and pull it off, please document it here. Make sure you have a good moisture meter. Good luck!

mischief · 04-10-2013, 06:39

Thank you very much Minaret,

I'm hoping to start my major out of water next year so that gives me a bit of time. I know how fast time goes by though and how long it can take to sometimes organize everything for a project so this is a big help.
Doing one thing had led me to many at the moment which I know is not unusual so here I am headliner out but new ones built insulation done new wiring run and connections done but need to install panel, reassemble everything. Water tanks to storage/tank conversion mostly done composting head just starting plus all old plumbing removed, upholstery about to start then refrigeration and rebuild ice box etc etc..... Wouldn't it be nice to start one project and be able to just finish it? I just can't half do something and if I'm rebuilding rotting headliner then I must fix the issue and tend to everything while its all apart like new wiring since its about that time and if I'm doing that and have to mount lights in my new strip headliner I better put them right where I want and I better build custom lights since they after countless descends they just don't make a led light I'm halls with and if there's all new wiring why reinstall an old panel and.......thank goodness I'm close to the top of the bump and about to start putting everything back together.

The information on this site is an excellent resource and the creative minds behind a lot of projects.

**minaret** · 04-10-2013, 07:47

No problem. Ask away if you need to know more about this, or need help sourcing anything. If you actually pull this off and document it well here, you will be one of the "creative minds" at CF!

Crayfish · 25-12-2013, 12:08

Hi Minaret, hi Mischief,

Haven't been in the forum for a while. In case you still need to know some details concerning our homemade Hotvac feel free to write a comment on our website
http://hitch-hike-heidi.de/?page_id=271

I bought all items on ebay. It's not that expensive if you are lucky.

Volker

**minaret** · 25-12-2013, 12:10

Quote:

Originally Posted by Crayfish

Hi Minaret, hi Mischief,

Haven't been in the forum for a while. In case you still need to know some details concerning our homemade Hotvac feel free to write a comment on our website Hitch-Hike-Heidi.de | Lotterleben par excellence.

I bought all items on ebay. It's not that expensive if you are lucky.

Volker

Thanks!

rogerball0 · 22-01-2014, 05:58

Hi Crayfish,

Thats pretty cool, and there i was thinking i was the only one to have come up with a homemade solution to this system, did you get your boat completely dry or drier?

I found i just couldn't (no matter what temperature) get the readings down to zero, i'm quite amazed how similar my set up is to yours, i too used epdm rubber to make the envelopes the wires sat in. I experimented with different types of under floor heating systems as they are cheap here in the UK (£30) and got the moisture readings moving downwards with them.
Where i got things flying was when i had a couple of silicon rubber mats made, they were a bit dearer (£200 each) but justified the expense relative to what a boatyard would've charged (£1000's).

Here's my set up cheers:

https://picasaweb.google.com/1101828...eat=directlink

Roger