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Re: 1/32 scale HK4 Spruce Goose

PostPosted: Sat Feb 26, 2011 9:11 pm
by HO229
Hello Bill,
Polyester based resins display excellent mechanical and application properties.
Polyester bonds via a mechanical bond (in this application) and polyester resins display satisfactory environmental characteristics and to date I have had no issue with pealing. Without going into great detail filler/resin that has aged for some time will become brittle.

SIDE NOTE:
Resin on the mixing board will cure faster than resin on the model because the catalyst and the hardener experience an exothermic reaction when mixed together.
If it’s one wish to accelerate the exothermic process (burn down the shop) add some MEKP to the polyester base.
To date, It has been my experience that polyester fillers works better on wood than they do on metal, while metal is porous wood seems to display better mechanical bonding characteristics. Wood and polyester resin/fillers display comparable sanding properties. What this means in a nutshell; while sanding a transition, a lip typical does not form at the junction of the resin and the wood.


Cheers,
Dave

Re: 1/32 scale HK4 Spruce Goose

PostPosted: Mon Mar 07, 2011 12:54 am
by BillG
Aware of endo and exothermic reactions. Especially when you add too much hardener on a 90 degree day. :shock:
I have a good deal of experience using bondo with wood, repairing custom wood trim, pillar bases, etc on homes. The custom woodwork would (woodchuck, wood, would) :D be expensive to replace, as they would need to contract someone like yourself. :D You must have a low moisture content in your wood, as I have had issues with obtaining bonds good enough for perfect feathering. Then again, the resin really needs a full 24hr cure, or even more, for best feathering ability. Much of what I've done has been readily finished. I wish you could see some of the insane things I've done, such as using cardboard-tape dams on curved arch trim, replacing large rotted areas with bondo. Right at the critical point, you have to move at 9000mph with a cheese grater, while on a ladder. I can usually dial things like that in perfectly, with about 3 coats.

Re: 1/32 scale HK4 Spruce Goose

PostPosted: Sat Aug 04, 2012 10:19 pm
by Adventureguy
I am TRULY disappointed that this thread died.

The greatest description of the greatest model of the greatest flying boat...

Its demise deserves the greatest sigh!