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[mbm999]

Hi all,
I'm building an Aquarama and have decided to epoxy the hull (and maybe the deck).
What are the pros and cons of omitting the glassfibre matting?

Cheers
Mark

[John W E]

hi there


There is no real disadvantage - as long as - there is no flexing of the skin material which the hull is made from.


That is the only problem.   If there is too much flexing within the hull, the epoxy may tend to crack if it is applied too thickly.   Several hulls which I have built in the past, I have coated with pure epoxy,   


My method of coating a hull with epoxy is apply 2 coats and allow that to harden completely (for say one day and a half) rub the hull down with coarse wet n dry until you have removed all the blemishes out of the epoxy and it is nice and smooth.   Then I apply a 3rd coat and when that is still wet I smooth it out with an old scraper - such as an old plastic bank card - this in turn levels it all out.


I allow the hull then to harden off and finally give it a good rub with a fine wet n dry.


Hope this helps you.


John

[Circlip]

What you may not know Mark, is that John had full size lamination processes in industry so  - -- -. One thing I would add is that in my own hobby mouldings, I've used lightweight Nylon fabrics instead of Glass mat for laminating wooden fusegulges and wing coverings in me toy R/C gliders. Reason being, in the event of an "Arrival", Glass is what it says on the tin and breaks. With nylon, you end up with a cloth bag containing the bits for rebuild.   


  Regards  Ian.

[mbm999]

Hi John,
Thanks for the informative reply.
Could I ask a couple of questions:
After the first coat, do you allow that to fully dry and then sand (or maybe left tacky and then the 2nd coat)?
When you say "coarse" and "fine" sandpaper, would you say that was (180 and 320)?
I'm assuming that you would deem a sub plank and planked hull rigid enough to just use epoxy (I've also epoxied on the inside)?

@Ian - Ha, that made me laugh! Something (else) to think about.

Cheers,
Mark

[John W E]

hi there


Ian that made me laugh as well 


As far as coating the hull goes - after the first coat of Epoxy, I allow it to dry for about 2 hours.  Or, until the Epoxy is touch dry.


Then I give it a 2nd coating of Epoxy resin and this I allow to dry for at least 2 days.


With regards to your hull flexing, it sounds as though it is quite rigid.  So it should be okay. 


Sanding - it looks you have about correct with the grades of wet n dry.   I have known - when I have had a bad finish on the hull - where the resin has run to wrap 80 grit in a block of wood & take off the high spots or the runs with that grade of wet n dry.


Cheers - John

[mbm999]

Hi John,
Thanks for that.
I can certainly see me getting some runs so that's useful to know too!

Cheers,
Mark

[Circlip]

And although it infers it Mark, use WnD WET, or like normal grit papers, it clogs and b****rs the surface.


 Regards  Ian.


 A splash of washing up liquid in the rinse water also helps.

[mbm999]

Hi Ian,
That's a really useful tip, thanks (I would have used it dry  ).


Cheers,
Mark