Replies

1. 
   Tao | Dec 18, 2003 05:37am | #1

   First thing that comes to mind is Urea-formaldhyde.  It's rigid, waterproof, very strong, and should hold up in the highest heat a human can stand.  I use it for veneering, and it seems like it would fill the bill.

   Second thought is Resorcinol.  Similar characteristics.  Haven't used it, but it's used in a lot of similar applications.

   Third thought is epoxy.  Most of them soften around 300 350 deg F, and you have to make sure that the epoxy wets the surface well or you can get bond failure.

   I don't know enough to make a firm recommendation, but these bear looking at.  Sounds like shock resistance would be important, too.

   Are these for restorations, or for new rifles?  Seems like composite would be the choice for new ones. 

   Michael R

1. 
   MichaelPB | Dec 18, 2003 08:54am | #3

   I like the idea of Urea-formaldhyde as it seems redily available and isn't a PIA to deal with.  The barrels get hot enough to boil water and that heat does get transfered to the handguards.

   Guns are sort of like woodworking tools, there are guys with crappy tools who turn out great work, guys who buy the best of everything but never use it, and the guys who have to have what others don't. 

   The handguards I am making are for those who want want others don't have, not any real world reason.  Some want them because they love wood.  The real handguards are plastic but some people just have to be different.

   I make mainly restoration stuff for restoring vintage machineguns, you can see the stuff I do at:  http://www.mgstocks.com

   Michael

1. 
   HowardAcheson | Dec 18, 2003 11:40pm | #8

   You might want to contact DAP/Weldwood and ask their technical folks about the heat tolerance of the urea formaldehyde (Plastic Resin).

1. 
   MichaelPB | Dec 19, 2003 01:59am | #9

   Thanks, I sent an email to DAP today.

2. 
   Jamie_Buxton | Dec 18, 2003 08:53am | #2

   When you say "high heat", what's your spec?   100 degrees F?   120? 150?  If you have a specific temperature or test condition, maybe people can supply better advice.

1. 
   MichaelPB | Dec 18, 2003 08:56am | #4

   The higher the heat the better.  Some of these will go on legal Class II firearms (civilian owned machineguns) and so will get at least 220 degrees.

3. 
   ian | Dec 18, 2003 04:55pm | #5

   Michael

   I've used one of those Australian assault rifles.  I don't remember how the wooden piece was constructed but I do remember that the guard was in two pieces and the inside had a relatively thick (say 1/32) metal heat shield.  I think the metal was aluminium and the thickness may have included an aspestos (sp?) layer between the metal and the wood.  From memory there was no heat shield in the stock.  Again from memory the rifle was based on a Belgium design 7.62 made by FN (?).  I think the weapon was a NATO standard at on time.  You could try a search on rifles and see if the spec is on the web somewhere in one of the arms archives.

   As to heat, my memory is that the fully automatic version had a different guard to the semi auto version.  Also I've seen rifles, with plastic guards, where after nearly 1000 rounds in quick succession, the outside of the guard is too hot to touch even with gloves.  The barrel of the example I'm thinking of was still too hot to touch with bare hands almost an hour after firing stopped.  So my guess is that the barrel temperature got to well above 200 deg C, say over 400 deg F.

   Ian

1. 
   MichaelPB | Dec 18, 2003 07:51pm | #6

   Ian,

   Your recollections are quite accurate. 

   They get very hot, now most of the ones in civilian hands don't get shot that hard but I want to make these as good as possible.

   Here is a link to a picture of some of the Australian handguards that I redworked by adding a new layer of veneer to the outside.

   http://mgstocks.com/l1a1hg.jpg

1. 
   ian | Dec 18, 2003 11:33pm | #7

   Michael, I remember the vent holes as being larger, especially on the full auto version.   My guess is the heat shield is the critical element in the design.