When I bought my part built kit most of the the interior tunnel panels have been somewhat half heartedly riveted on. Luckily the floor was welded on by the manufacturer.

The tunnel panels are haphazardly riveted on and in some places no sealant has been used. I really need to drill out the existing rivets and reattach the panels using new rivets and sikaflex etc. But if I drill out all these rivets are the ends going to rattle around inside the chassis and annoy me forever? Should I put sealant into the holes to try and stick the loose bits together?

Well if you're going quickly enough you won't hear any rattling

More seriously a quick squirt of waxoyl into the tubes will prevent any rattling and protect from rust inside the tubes.

I was also going to suggest wizzing some waxoyl in there.

Just make sure you're not planning on doing any welding of those chassis tubes later on. Waxoyl and welding is a bad mix.

Hi. Don't drill out the rivets - you will open out the holes. Drill off the head and and punch the stalk into the tube. A little bit if expanding foam will stop any rattling.

if you worrying about the noise of the rattling rivets thats the last of ye worries. the 99 DB next to your ear will take care of that.

:O)

Yes, agree with the above. Just drill sufficient off the heads to be able to punch the rest into the chassis tube. ie just enough to almost start a chamfer on the body panel, but certainly not drill all the way thru.

Squirt in the waxoyl, so they dont rattle and the tube dont rust... Double bonus with Waxoyl!

Enlarge one whole at the end of each tube, shake the rivot ends out (or use a compressor to blow them out?) then blob a small weld over the large hole.