RC India

RC Equipments => Tools, Materials and Building Techniques => Topic started by: AnjanBabu on November 08, 2013, 10:48:45 AM

Title: Can Thermocol be hardened?
Post by: AnjanBabu on November 08, 2013, 10:48:45 AM
I built an air boat and the sponsons are hot wired from thermocol to keep the weight low. Unfortunately, the edges of the sponsons are sort of delicate and they break and crumble easily. Is there anything I can coat the sponsons with, that will make it a little tough? It's got to be waterproof and shouldn't add much weight.
I was thinking of Araldite, but inquiring for better options, if there are any.
Title: Re: Can Thermocol be hardened?
Post by: sanjayrai55 on November 08, 2013, 11:05:19 AM
Dilute Fevicol with water to 50%. Apply a thin coat. Next, lay tissue paper on the wet coat, and apply 2 more coats. Let dry. You will have a tough, hard skin which is easily sandable :D

Note: do NOT use synthetic tissue
Title: Re: Can Thermocol be hardened?
Post by: AnjanBabu on November 08, 2013, 11:12:18 AM
Sanjay bhai, Is that waterproof?  ???
Title: Re: Can Thermocol be hardened?
Post by: saikat on November 08, 2013, 11:14:05 AM
Snazzy shape - you came up with this yourself ?

looks like something Annakin Skywalker would be driving
Title: Re: Can Thermocol be hardened?
Post by: saikat on November 08, 2013, 11:17:29 AM
Sanjay's method is good - to waterproof paint touchwood over the fevicol tissue matrix
Title: Re: Can Thermocol be hardened?
Post by: AnjanBabu on November 08, 2013, 11:21:28 AM
Saikat, yes, scratch build.

Thanks, I will try the tissue and touchwood ideas. :thumbsup:
Title: Re: Can Thermocol be hardened?
Post by: sanjayrai55 on November 08, 2013, 11:24:19 AM
Yes, waterproof when dry. Then as Saikat says, touchwood, or even paint

Saikat,  :thumbsup: :thumbsup: very Skywalker !!! Pod Racer  :rofl:
Title: Re: Can Thermocol be hardened?
Post by: foamybuilder on November 08, 2013, 11:37:16 AM
use coro for those winglets
Title: Re: Can Thermocol be hardened?
Post by: AnjanBabu on November 08, 2013, 01:14:44 PM
foamybuilder, Those are the motor mount post. It's an air boat. :D
Title: Re: Can Thermocol be hardened?
Post by: KALYANPRODHAN on November 08, 2013, 01:41:59 PM
I prefer to cover with coloured polythene 2" Tape for smooth surface. However, this is used in free flight foam glider.
Title: Re: Can Thermocol be hardened?
Post by: foamybuilder on November 08, 2013, 02:00:41 PM
Quote from: AnjanBabu on November 08, 2013, 01:14:44 PM
foamybuilder, Those are the motor mount post. It's an air boat. :D

Plane or boat, strengthening method would remain same. What i mean is laminate it with 2mm coro.
Title: Re: Can Thermocol be hardened?
Post by: AnjanBabu on November 08, 2013, 02:11:01 PM
KALYANPRODHAN, that works to keep the thermocol from breaking off, but it still lets the edges deform. Looking to make it hard and stiff at the edges.

foamybuilder, I used 3mm sun board for the mounting post, no strength issue there. Only the sponsons are a little delicate.
Title: Re: Can Thermocol be hardened?
Post by: Aman23 on November 08, 2013, 02:22:34 PM
will rubber paint work or will it destroy thermocol?  :headscratch:
Title: Re: Re: Can Thermocol be hardened?
Post by: sanjayrai55 on November 08, 2013, 02:52:38 PM
Use enamel or acrylic
Title: Re: Re: Can Thermocol be hardened?
Post by: sanjayrai55 on November 08, 2013, 02:53:25 PM
Wth is rubber paint anyway?
Title: Re: Can Thermocol be hardened?
Post by: Nithinraj Kotian on November 08, 2013, 03:56:21 PM
anjan i suggest you to use thin canvas cloth dipped with fevicol glue to cover the foam.  :) 
Title: Re: Can Thermocol be hardened?
Post by: Aman23 on November 08, 2013, 04:08:30 PM
rubber paint is used for waterproofing surfaces. it is often used as a coating on iron sheets to prevent them from rusting.
here is a spray version demo on youtube: http://www.youtube.com/watch?v=1qPXhdBuCn4
Title: Re: Can Thermocol be hardened?
Post by: sanjayrai55 on November 08, 2013, 05:36:35 PM
OK. The rubberized undercoat. Why would you want to paint a model boat with that? Lousy stuff for finish
Title: Re: Can Thermocol be hardened?
Post by: Aman23 on November 08, 2013, 06:04:05 PM
that is upto AnjanBabu to decide...  :P
Title: Re: Can Thermocol be hardened?
Post by: AnjanBabu on November 08, 2013, 06:46:42 PM
Nithinraj, I already covered it with tissue and Fevicol, got to wait and see how good a job I've done.
Not a bad idea, using a fabric.

Aman, I'm looking for some easy and cheap techniques. :D
Title: Re: Can Thermocol be hardened?
Post by: Nithinraj Kotian on November 08, 2013, 11:06:09 PM
anjan check this out
Title: Re: Can Thermocol be hardened?
Post by: AnjanBabu on November 09, 2013, 01:33:06 AM
That's not bad, looks neat.
Going to find out in the morning if i'll have to hotwire new sponsons, the tissue+fevocol coating looked very messy and uneven, it was my first time. :(
Title: Re: Can Thermocol be hardened?
Post by: Nithinraj Kotian on November 09, 2013, 08:07:25 AM
local tailor shop will have those canvas cloths ask for 2" width and 1 meter length.
Title: Re: Can Thermocol be hardened?
Post by: AnjanBabu on November 09, 2013, 12:25:42 PM
Tried sanding the tissue coating and it didn't turn out as smooth as I expected.  :(
Hot wired two new pairs of sponsons, going to try using newspaper instead of tissue on one pair and Nithinraj's suggestion of using Canvas cloth on the other.