Acid blood that can eat through metal, but not Drakes bones?

[SM]

The scar in the script:
"Nasty scar curling his lip into a sneer."

[Wweyland]

Seems they toned that down for the film.

[JokersWarPig]

I don't think there was time to see how bad it would have affected Drake. We see the impact and the immediate reaction and him go down. What happened after that was probably pretty gnarly.

I kinda wish Drake had made it to the ops battle.

[Wweyland]

Would have been interesting to see Drake in the Ops battle, they could have held their ground better.
He would have probably used the half-full flamethrower that they mention but don't use?

[SM]

Ripley was supposed to use that originally.

[Wweyland]

Ripley was supposed to use that originally.

You mean in an earlier draft? A flamethrower could have been more useful in the vents I think.

[SM]

Only if you're firing behind you.

[JokersWarPig]

Only if you're firing behind you.

So very useful if you're Vaz

[SM]

Not so much if you're Ripley.

[NetworkATTH]

They probably excised the flamethrower idea because, you know, they had a working flamethrower and setting the sets on fire was probably dangerous as hell. There's ways they could work around that cleverly but, yeah, if that was the case they probably omitted it from the final shooting script because it added too much work unnecessarily. And it adds a more dramatic punch when Ripley finally uses the flamethrower in the nest.

[OpenMaw]

Gotta remember the Vietnam allegory at work here too.

Drake was basically the victim of a sapper.

[SM]

I think it's more Vasquez ignoring intel.

[HuDaFuK]

It's a scar.  I don't know if Rolston has it or if it was makeup.  Drake was scripted to have a scar.

Fairly certain it was makeup, i don't recall seeing it in any of his other roles.

As for the original poster's question, the answer is simply that you can only do so much damage with makeup before you'd have to start literally melting Mark Rolston, and I'd imagine that wasn't in his contract.

[machines1047]

The Xenos in Aliens could be a different but similar species than Big Chap. Could also explain the differences in Body and Behavior.

Similar thinking along the lines above, after I posted this, I had a thought, a face hugger, being as defenseless as it is (other than being very quick and instinctual, what real defenses does a face hugger have? None, in my opinion.) I decided while it's probably never been proven, or really even thought of by anyone writing or scripting canon, it could very well be plausible that a face hugger would have a higher concentration of acid for blood, than say a more aggressive and defensive adult who has teeth, claws and a tail and can use them with vicious savagery.
         With that said, yes, I agree with many replies stating that we really didn't get much of a shot of Drake after being splashed and the quick shot we did get, time hadn't lapsed too much as well, so there could be further affects.