Got a Scott mtb frame that I am considering building up as a do verything type road rider. This has the "M" brakes on the chainstays. It appears to have spent a good amount of time outside. The "reddish" paint has faded to a pink everywhere except under the frt. derailleur clamp and a few other places. On a lugged frame it would be pretty easy to look into the chainstays from inside the bottom bracket shell for rust. Because it is tig welded, there are just small, about 3/16", diameter holes going to the frame tubes. So, is there a reliable way to check and see if this frame is sound, or should I just look further?

Thanks,
Robert

Mtn tubes are thicker than normal. I wouldnt worry too much about it.

Often you will see rust around the bb itself (internal). Water can collect in that area. Pull the seat post and look down the seat tube towards the bb, or better yet, pull the bb.

Here's a picture of a rusty one.

The bb is out and the bb is clean , so mmust not have taken on much moisture at all.

Thanks for the replies.