View Full Version : Finishes: undercoating or bedliner on handguards

Scott S
February 05, 2001, 11:56
Went to the autoparts store to buy some truck bedliner to coat my steel handguards. On a whim, I purchased a $4.99 spray can of 3M rubberized undercoating instead of the bedliner.

I applied several layers of this 3M stuff to my prepped handguards. Sprinkled a little sand (from the kid's sandbox) between coats; this gave 3M stuff a little additional texture. The finished product is somewhat soft to the touch and matte in appearance; it's about 1/16th of an inch thick.

My only concern is how well this stuff will hold up to heat. I'll test it this weekend at a shoot, but I'm curious whether I should be prepared to deal with runny 3M stuff.


[ September 09, 2001: Message edited by: gary.jeter ]

Dan at VOW
February 05, 2001, 12:13
Get ready for the runny stuff, wait until you go to clean the rifle and get some solvent on your hands. You will leave fingerprints or have patches of it coming loose. The bed lining material in either standard or rubber coating is much more duarable. Sorry for the bad news. Dan.

Scott S
February 05, 2001, 12:18
Thanks for the reply. Didn't think about the issue with cleaning solvents--oops. At least it was only a $5 experiment.

I will take the handguards off before cleaning until I have the spare time to strip and recoat them.

February 05, 2001, 14:21
I did mine like that....

Never set right, and easily scratches/peels off.

I stripped it with lacquer thinner, and sanded, 50,80,120,220,320,400,600 grit.

Found that 600 was too smooth and slick, so roughed it up with 320 again. It looks and feels great!!!

February 05, 2001, 17:49
yep not a good idea undercoating never gets hard,you could try stonegaurd though (stuff they use on the lower 1/4 of many trucks/SUVs)stuff gets hard has a texture to it but you must paint over it for color -Jay

The first ones expensive,but after that,they're all free.

Farmer from Hell
February 06, 2001, 18:02
Somebody here went to HD and got some Al. flashing in a role and cut some pieces that would fit inside the HG's and I think that is what I will do when I get around to building my STG.


What part of Shall not be Infringed dont you understand pinhead?

February 06, 2001, 21:07
Use Brownell's Spray Grit.

Works GREAT!

Feels like Skateboard Tape but less sharp and "sandpapery".

$8 a can from Brownell's.

Use for cheap (stippling) on handguns as well!

ironman0311 - Ohio

February 07, 2001, 11:36
Pretty well covered already, but yeah, stay away from the undercoating.

I tried the undercoating to spray my homemade pistol rack inside my gun cabinet. Placed the pistols in after letting the stuff dry for 2 days. Next day i took one pistol out, and the crap was stuck to the pistol, and i mean all over.

Went to the store, bought some bedliner, pulled out the pistol rack, then applied 3+ coats over the undercoating. Turned out okay, but probably would have worked better with bedliner the first time around. Had to clean all the pistols as well...more quality time with the little gems http://www.fnfal.com/forums/wink.gif

Scott S
February 08, 2001, 10:42
Thanks for all the replies. I stripped the undercoating with mineral spirits and a nylon toothbrush; it came off easily. I'm glad that lesson was relatively painless.

Back to the auto parts store for bedliner. I'll coat the guards tonight and give her a whirl on Sunday. If the bedliner doesn't keep my mitts cool enough I'll also give the aluminum flashing inserts a try.

What a great resource this board is. I appreciate the input from you all.

September 09, 2001, 18:12
moved to FAQ

September 09, 2001, 19:26
Guys, I GunKoted my original metal STG hg's and of course this gave them a very good look and protection since it was on top of a fresh parked finish. I tried the Auto Zone insulation/metal tape treatment and I was one of the members who posted the insert templates, just right click and save.

Sad to say though, all of this effort only DELAYED the transfer of heat to the outside of the hg's. Where the metal of the hg's and the gas nut and gas block touch the hg, the transfer of heat goes through here and eventually warms it up to the point it can not be held anymore. I did all of this to the Tapco plastic hg's too. Same thing, it delayed the transfer of heat, but these never got to the point where they could not be held. They did get quite warm now too, just not scalding like the metal ones get!

I finally did what I should have done in the first place, ordered the $50 DSA handguards and be done with it! These get pretty darn warm too but you can still hang on to it unlike the metal ones. They say the original R1's work great too, just will probably have to refinish somehow.

Just trying to save ya'll some bucks and time. Been there done that sort of thing! :)