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[Martin13]

Some time ago and I can't remember why, I purchased a 2 part Epoxy Resin named NHP Epoxy Finishing Resin.

In reading the instructions and looking for cure/set times, I noticed the following statement.


Working Time 20 - 30 Minutes, Sets In 3 Hours, Can be Handled and Sanded in 12 Hours - Fully Cures In 24 Hours.

My Question:

Would this epoxy resin be classed as 30 minute resin, 3 Hour resin, 12 hour resin or 24 hour resin????

How does it differ from the 30 minute, 12 Hour and 24 Hour types

I am currently setting in prop shafts to a GRP hull and it was suggested to use 1 hour epoxy although 24 hour epoxy would be better.
Seriously Confused.

Martin doon under

[Martin (Admin)]

"30 minute, 12 Hour and 24 Hour types"

I think that refers to the "setting" time, which I take to mean it's reached 95% of it full "cured" hardness.

[Colin Bishop]

Martin, first of all I wouldn't use finishing resin as a glue, it's not what it is for. Finishing resin is usually a thin resin intended to provide a smooth finish over an existing surface. To fix your shafts you need a combination of glue and filler. With just about all glues, there is a time between when they set and when they reach their full strength which can be up to a week in some cases. With epoxy glues, the longer the nominal setting period, the better the eventual bond so that a 24 hour epoxy will give you much greater strength than the five minute variety. The latter is perfectly OK for sticking on fittings etc. but when it comes to installing proptubes and supports you need the very best bond you can get.

Everyone has their own way of doing these things but if I were fitting the running gear to your Vanguard I would use Araldite 24 hour epoxy glue for the main fixing. Once it has set hard (after 24 hours!) I would then use glassfibre paste http://www.force4.co.uk/b/109/Plastic-Padding.html to fill in any remaining gaps and bed the tubes into the inside of the hull. This sets in half an hour or so and will support the tubes, help keep them rigid and reduce vibration. By embedding the tubes in a surrounding of GRP paste as they enter the hull you will effectively have built them into the structure which is what you want. The GRP paste is better than just using ordinary filler as it has short glassfibre strands in it which significantly increae its strength.

Hope this helps,

Colin

[Martin13]

Martin,

Hope this helps,

Colin

Colin - it sure does help - another perfect answer from a Master Builder

I will follow your example and buy some 24 Hour Araldite and in the meantime, find out what this finishing Epoxy is used for.

Thanks a heap from down under

Martin

[tigertiger]

...and in the meantime, find out what this finishing Epoxy is used for.

Hi Martin

It's used for getting a glass like hard finish on wooden surfaces. like on some of the yachts and the Aquarama Riva type wooden gentlemen's launches.

[Martin13]

...and in the meantime, find out what this finishing Epoxy is used for.

Hi Martin

It's used for getting a glass like hard finish on wooden surfaces. like on some of the yachts and the Aquarama Riva type wooden gentlemen's launches.

Thanks TigerTiger in China.

Then you should also be able to answer the next 2 questions

1).  On my Brave Borderer build, I have used block balsa for the bridge area superstructure and having a hard time in getting the surface flat and even including always filling in small dents. can this finishing resin be brushed on to fill voids and add strength to the balsa...

2). Currently way down here in Oz the temps during the day are in the mid 40's C and at night drop to high 20's - low 30's C. Am I still able to use Araldite, Epoxy resins etc in these temps. Does the temp effect the cure rate????

Martin doon under

[tigertiger]

Hi Martin

1/
So sorry I don't have the answer on this one. It may work but it would be a bodge. Bodges have a habit of showing up.
The problem is probably related to the loose grain of the balsa. Balsa is also a pig for dents. I haven't mimicked steel superstructure, but i know  lot of the builders on here use a sheet of plasticard attached to the surface of the wood with double sided tape.

2/
Higher temps speed up the cure rate. I am not sure if there is a max. But less than 22 is a problem.
High humidity however can cause problems.

Sorry I cannot be of more help.
But someone on here will have the answer.

[oldiron]

1).  On my Brave Borderer build, I have used block balsa for the bridge area superstructure and having a hard time in getting the surface flat and even including always filling in small dents. can this finishing resin be brushed on to fill voids and add strength to the balsa...

Martin doon under
[/quote]

  May I suggest the following. Its a method suggested to me by ggeorge over on the TID tug build thread and it works well. Seal the balsa surface with cyano drizzled over the whole. When set ( few seconds) use automotive body shop "Icing" over th ewhole surface. Sand when set, , prime with scratch primer and spot fill with additional "Icing" where necessary. Sand again and prime again. The block should now be ready for paint. I've just finished using this method on my Smit Nederland (see Smit Nederland.....again) on the wood parts. When done carefully the finish looks like steel. ggeorge did the same on his TID on both the hull and deck house.
  An additional method I've used over wood is to coat the wood surface with water based contact cement. Roughen the surface of styrene (cut to size), and cover with water based contact cement. Apply the styrene to the wood. See the photo for the tanker deck.
  I've heard it said that the styrene will separate from he  wood with contact cement. I haven't run into that problem in all the years I've been doing it. I suspect it may be because I roughen the contact surface first.

John

[towboatjoe]

Martin doon under,
I use 1/4 ounce mat and sometimes panty hose with epoxy finishing resin to get a smooth finish over balsa wood. Here's a pic of a balsa hull covered with the mat and finishing resin.

[Roger in France]

Now you knew you were giving rise to comment!

Do you wear the panty hose over your face while you paint or on your legs to keep warm!

Roger in France.

[Martin13]

Oldiron and Towboatjoe.

Thanks for the suggestions. I especially like that Icing filler stuff - sounds like the way to go. Where in the US can I buy it from - is their a website that I can order online?? I prefer to stay away from styrene to cover the balsa as the superstructure is all curves. I did notice on one part where I spilt CA glue, the balsa went quite hard.

Towboatjoe - like the finish on your hull - now I know where this epoxy finishing resin is used, just need to steal swmbo's panty hose- Thanks for your suggestion and pics

Roger in France - I was wondering when you were going to make a comment - had a good laugh

Martin doon under

[oldiron]

Oldiron and Towboatjoe.

Thanks for the suggestions. I especially like that Icing filler stuff - sounds like the way to go. Where in the US can I buy it from - is their a website that I can order online?? I prefer to stay away from styrene to cover the balsa as the superstructure is all curves. I did notice on one part where I spilt CA glue, the balsa went quite hard.


Martin doon under

  I Canada we buy it a good auto parts stores, particularly those that deal with body shops. Its an across the counter item.

John

[tigertiger]

Why, what can you buy under the counter in Canada's auto shops?

[oldiron]

Why, what can you buy under the counter in Canada's auto shops?

He He.......I can't say.....this is a family site.....

John

[oldiron]

Here's the web site for the manufacturer of that body Icing:

http://uschem.com/index.cfm?page=productDetail&id=57&pid=1

John

[tigertiger]

Car body icing I hope

[Circlip]

Epoxy resins were/are used extensively for covering model aircraft wings having an expanded polystyrene core 'cos it don't melt the styrene. Depending where you use it, neither polyester or epoxy resins NEED a glass based "Carrier" - Carbon-fibre? I've used both silks and nylon as a covering media on toy aircraft, when yer prang with glass it breaks up, when yer prang with silk or nylon, it becomes a self contained bag.

  Regards  Ian.

  OOOOps forgot the dire warnings, dress suitably, full facemask, breating apparatus, Marigolds.

[tigertiger]

Thanks Circlip, I think you have half answered another question I had.

Why FG? What does it add that other materials that will hold resin cannot?

Is it that glass is stable/won't rot and goes on thick?

[Circlip]

Yer'll have to check with the "Chemists" Tiger, I ain't getting into THAT ONE again, Horses for courses.     

[Martin13]

Here's the web site for the manufacturer of that body Icing:

http://uschem.com/index.cfm?page=productDetail&id=57&pid=1

John

G'day John,

Thanks for the link. I sent the company an email asking for info on Australian Distributor or somewhere in Canada/USA where I could purchase preferably on-line(easier to make payment). May have to buy a box of 6 tubes - sounds like a lifetime supply or an awful lot of model boat repairs. Can you give me an idea what you paid in Canada for a tube

Martin doon under

[oldiron]

Here's the web site for the manufacturer of that body Icing:

http://uschem.com/index.cfm?page=productDetail&id=57&pid=1

John

G'day John,

Thanks for the link. I sent the company an email asking for info on Australian Distributor or somewhere in Canada/USA where I could purchase preferably on-line(easier to make payment). May have to buy a box of 6 tubes - sounds like a lifetime supply or an awful lot of model boat repairs. Can you give me an idea what you paid in Canada for a tube

Martin doon under

Martin:
  I'll check with our NAPA Auto parts store, this morning, for the price. Thats where I get in my town. Have you checked your auto parts store to see if they have it. If you have an automotive body shop near you, I'm sure they'll be using it. You wouldn't want to buy a case of it unless you want to give it away to your friends. A tube goes a long way. When you get it, don't forget the hardener that goes with it.
John