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View Full Version : question AR foregrips made of Aluminum and heat transfer.....


Squid
04-09-2012, 12:35 PM
From my construction experience and working in shops, I can say aluminum's ability to suck energy out of you due to its fast heat transfer is completely different even from steel.

I've read that wood makes a nicer handing stock that plastic for that heat transfer reason.

I'd think aluminum would be the last thing I'd want to make a grip out of, or I'd at least want to plastic coat it like a Remington 887 shotgun.

Handling a lot of aluminum beams and tube frames you learn to either wear gloves and/or keep your hands off the material unless actually moving it.

It seems to suck energy and cause a certain discomfort even if you are sweating and it is cool, or vice versa. Sort of like a waterbed outside very narrow range will suck energy out of you as your body works to maintain correct temp.

Is this somehow not a problem for all those AR fore-grips?

osis32
04-09-2012, 12:43 PM
It shouldn't be. Most free float rails do not contact the barrel or gas tube so there is minimal heat transfer to that part. If the rail isn't hot the grip shouldn't get hot either.

osis32
04-09-2012, 12:44 PM
And even if it isn't free float the contact and heat transfer should be very negligible.

Grumpyoldretiredcop
04-09-2012, 12:44 PM
I've used aluminum railed handguards extensively on ARs for years. The only time I've ever experienced heat problems was with an M4 after multiple mag dumps... and it wasn't heat transferred from the barrel to the handguards, it was heat radiated from the barrel through the vents in the handguards.

Short answer: It's not a problem.

live2suck
04-09-2012, 12:46 PM
I have the RRA Half-Quad, and it is a solid piece of aluminum, but it's also adequately vented. I've also popped off 60 rounds consecutively for the fun of it with bump fire. It did get a little warm, but not hot enough to burn my bare hand.

Any properly designed hand guard or fore grip should have adequate air flow over it to prevent over heating. Also, compare the specific heat capacity and surface area of those large beams you're handling in comparison to a 1 lb. hand guard that is essentially hollow - less material to absorb energy, and more surface area to reject it. When you consider that you're not ever going to have sustained full-auto fire from your AR-15 this concern should quickly dissipate from your mind.

Just pick out something that satisfies your looks and functionality requirements and never worry about it again.

Squid
04-09-2012, 12:58 PM
during heavy firing.

I'm just thinking if I was going to spend any amount of time holding the weapon and watching and waiting Alum would be the last material I'd want, even if wearing thin gloves.

However, on a hot day or in sun heat would also be a problem, I'd think.

"hot" aluminum is more uncomfortable to handle than other materials.

Harrison_Bergeron
04-09-2012, 2:40 PM
I make things out of metal as my profession too and I have never heard of anyone making it a point not to hold aluminum unless necessary, let alone because it "sucks the energy out of you".

You need to be careful around aluminum in a fabrication environment because it does not show it's temperature like other metals, a piece that was just welded looks the same as a piece that has been sitting for hours.

Boltz
04-09-2012, 3:22 PM
during heavy firing.

I'm just thinking if I was going to spend any amount of time holding the weapon and watching and waiting Alum would be the last material I'd want, even if wearing thin gloves.

However, on a hot day or in sun heat would also be a problem, I'd think.

"hot" aluminum is more uncomfortable to handle than other materials.

Ok, I got what you are saying now - aluminum has a high thermal conductivity, hence its use in heatsinks. In other words it moves heat pretty well, so on a cool or cold day it would draw heat out of your hand.

As far as foregrips go, I've never used an Al one and most people seem to use plastic ones. But it wouldn't seem any worse than holding a cold beer or soda can for a while.

Squid
04-09-2012, 3:29 PM
working outside in construction and humping a lot of 2" alum. pipes or tubes or "AlumiaBeams" on a 'production' basis you will notice the alum is 'strangely' cold and oddly uncomfortable to handle after a few minutes.

Just seems like it would be distracting and not best choice.

Kitchen Tip of the Thread: you can defrost stuff really fast by just placing on an alum non stick cooking surface. It really sucks out the cold even though you look at contact points and say "nah, shouldn't make much diff, if any".

Sniper3142
04-09-2012, 3:46 PM
I've had aluminum handguards on my AR15s for several years. Never had or even heard of a problem involving heat transfer.

Peter.Steele
04-09-2012, 6:37 PM
I've got an aluminum free-float tube on mine, never noticed a problem.

That said, I'd much prefer aluminum over wood. I've never had a problem with cold, but I have run a G3 hard enough that the wood handguard / forearm were smoking and splintering.

CHS
04-09-2012, 7:37 PM
working outside in construction and humping a lot of 2" alum. pipes or tubes or "AlumiaBeams" on a 'production' basis you will notice the alum is 'strangely' cold and oddly uncomfortable to handle after a few minutes.


Here's the thing. That production aluminum you're used to is basically raw aluminum. The aluminum used in handguards has been Type III hard anodized, which generates a pretty thick layer of aluminum oxide on the surface. Aluminum oxide is not very good at transferring heat. ESPECIALLY compared to raw aluminum like what you're used to handling.

Because of this, handguards don't generally feel that cold and they don't pick up the heat from the barrel very well either.

If they were raw aluminum, you WOULD feel a difference.