Casting vs Laminating Resin

[seltzer_water]

Hi,

I'm trying to waterproof wood and I'm trying to find polyester resin locally. I found an art store that sells Polyester Casting Resin. How is this different to laminating resin (marine boat resin?) and can it still be used as waterproof resin?

Thanks!

[apex1]

No it can´t. Neither can laminating polyester resin! It is not completely water resistant like Epoxy resin. And it does not stick well to any material, especially wood.
What is the application you have in mind? How "waterproof" has it to be?

Regards
Richard

[seltzer_water]

i want to build a small wood box and use it as a tub in the winter using this design

http://www.motherearthnews.com/Do-It-Yourself/1995-12-01/Hot-Tub-Nirvana-For-100.aspx

I thought since it has to soak in water all the time like boats do you guys would know the most about resin :D

And I'm following this guide using acetone + resin for waterproofing

http://www.hares.net/boat/waterproofing.htm

And the guide calls for polyester resin...Is epoxy a new invention? :confused:

[ondarvr]

You can throw out almost all of the information in the link to the "secret waterproofing mix".

[Itchy&Scratchy]

Just out of interest, the site you have a link to is all about saving the planet, living green etc..........
and they are advocating using fibreglass?????????????

Resin is an oil based product!!! The sort of industry you guys are choosing to reduce is exactly the one you are now wanting to use.:?: :?:
Any thoughts??:confused:


Regards
J

[apex1]

No time to waste on these "religious" sites, sorry.
When you are going to make wood waterproof you can encapsulate it in Epoxy resin. Just smeere the goo on in two or three layers, tahts it. When you need some abrasion resistance add a glassfibre fabric.
Paint the surface, epoxy deteriorates under UV rays otherwise.

Regards
Richard

[gonzo]

There is epoxy casting resin. It is made by one of the companies in the list of "Evil Conspirators Against Our Holy Mother". You know, DuPont, CibaGeigy, one of those ;)

[Fanie]

Yes you can waterproof wood with epoxy resin, Seltzer.

A little bit of prep though. You need a pipe where the wood fits into. Then pour heated epoxy resin into it, and apply pressure to the pipe. Heat will cause the air in the wood to expand and bubble out. When the compressed air is applied the resin will be forced into the wood.

You then take the wood out and place it somewhere to cool and cure. You cannot use polyester resin, it cures too fast.

[Herman]

Come on, guys, don't make fun of him.

Fro waterproofing wood, please get some nice laminating epoxy or wood compatible epoxy (well, most epoxies are, some are just a tad better). I would suggest some product of West System, System Three or MAS Epoxy, probably there are more out there in the USA, but I am not too familiar on brands there.

Apply a first coat. Let cure. Sand.
Apply a second coat. Let cure for an hour or 2.
Apply third coat. Let cure. Sand.
Apply 4th coat. Let cure. Sand.
Apply a PU coating, can be transparent or coloured. If using a transparent one, make sure it has UV inhibitors. Epoxy degrades under influence of UV.

For applying these coats nice and smooth, West System has nice foam covered cardboard rollers. I am sure other brands have similar rollers. Also check the instructions that are on the West System website. Even if not using their epoxy, you will learn a lot.

[Fanie]

Come on, guys, don't make fun of him.
Dead serious. Can you suggest anything better to resin the whole piece of wood to the core ? How do you think wood gets treated for harsh environments ?

[Herman]

Do you see this guy putting his tub in an autoclave?

I know the system you describe, and it works wonders, it is just the virtual impossibility for a DIY-er to do this. So lets give him decent advise, which he CAN perform.

[seltzer_water]

sounds like awesome and great ideas, thanks for the inputs so far

but this little girl just needs something long lasting and easy 'cause her funds are limited. and the wee little tub's just going to fit into a bathtub and never going to see the light of day. it just needs to be able to take a beating from shower water and soaking water, much like boats do out in the wide open sea, except in a much gentler environment.

[gonzo]

A couple of coats of epoxy should work fine. Don't mind the joking.

[apex1]

And skimp on the sanding! Assuming you have a planed surface, for what would you need to sand it? I assume you´re not going to give a bathtub a piano finish??!
Apply three layers of epoxy resin, the absolute cheapest you can find is a perfect choice for that application. Do´nt worry, there are absolutely NO technical aspects you have to care about.
Apply the resin wet in wet. That means, when the first layer is NOT cured completely (i.e. you can press your fingernail in the surface, or it´s tacky), you apply the next one, when thats done, the last. Let it cure (min 24 hrs. above 24°C) in a warm dry place. The higher the temperature the better (do´nt burn the house). Than apply paint or varnish or even nothing, when there is definetively no UV light exposure.

Regards
Richard

[Herman]

... or if you do not care about slight yellowing. Which, technically, is not worrying.

[Fanie]

it is just the virtual impossibility for a DIY-er to do this.

Not really. With a little bit of resourcing it cannot be too hard to put together. Besides once you have it done you can always offer the service to others, and maybe make a couple of bucks offen it as well. Just note on the forum how many guys needs wooden stringers for their boats but doesn't know how to treat them.

[TollyWally]

I looked at your magazine plans. Taping the seams will help keep it waterproof. A little bit of extra work that will insure a better product is to make a putty by adding baby powder to the resin until it thickens into a clay like consistancy and packing it into the inside corners. this is called a fillet and the purpose here is to gently round the the inside corners. Fiberglass cloth, matte, or tape doesn't like sharp crisp edges. If you do this after the first coat of resin and then cover with tape for the next coat it will be a little nicer. A couple layers of tape and you're starting to talk cadillac here.

[bntii]

Skip the waterproofing and build a solid wood tub?

Build it up with planks and hoops like a barrel.
Use 5/4 x 6" redwood or cedar deck boards. Buy 8' boards so you get three pieces out of each board.

Will take some skills learned and time but more fun and nicer than the ply box with resin splashed inside..

Like this just smaller:

http://www.cedartubs.com/ebayphotos/1205877398Ofuro%20in%20the%20Winter.JPG


Or just buy something like this?:
http://www.gototanks.com/images/products/ARM-10116_sm.jpg

Will cost less than the epoxy needed for the ply tub..

[seltzer_water]

I looked around for some wine barrels but they were ridiculously expensive

that plastic tub still looks a bit big i only need something about 1.5 feet wide 2 to 3 feet long and 2 to 3 feet tall

how come you dont need to waterproof the plank bathtub? won't it rot?

btw i found this resin

http://www.westmarine.com/webapp/wcs/stores/servlet/producte/10001/-1/10001/232527?&cid=chanintel&ci_src=14110944&ci_sku=232527

the filler blend's $20 is that acceptable?

[Yerba1]

Dr Rot has the goop for which you're searching. Google it - you can order it shipped directly to your mother earth project center.