Recommended approach to deal w/ holes for insulation pins when using Dynamat?

[dakota]

I'm planning to cover my floor pan and firewall with Dynamat after applying a coat of POR-15.   When I pulled the stock fiberglass insulation out, there were a number of the plastic pins missing that were supposed to hold the insulation pads in place.  Most of these unplugged firewall holes had some amount of rust running downhill like what's shown in the picture.  I don't think the Dynamat needs the  pins to stay in place, but should I insert the pins through the Dynamat anyway to fill the holes?   Not worry about filling them?   Would I be better off cutting the head of the pins short so they fill the holes and then cover with Dynamat?    This last approach seems to make the most sense to me, but I would really welcome hearing what others have found works or doesn't work.

[dutch]

I used a heat gun to heat the dynamat and pushed it somewhat into the holes.

[anlauto]

I put the factory insulation right over top of the Dynamat

[67vertman]

If it was me, and it will be soon  as I am doing the samething soon, I would fill the holes with sealer or weld them up to prevent water from getting in again.

[Skunkworks Challenger]

I put the factory insulation right over top of the Dynamat

Yes, this is what I did.  It covers the Dynamat for a "stock" look and increases the effectiveness.

[burdar]

Push the pins through the holes even if you don't use the factory insulation.  Also, I'd rethink using POR. 

[dakota]

Burdar, please tell me more about your concern regarding the POR-15 application to the floor plan.  Thanks.

[burdar]

I tried it and it was a PITA to use...very messy and it doesn't level out nice. I also used the POR exhaust manifold coating and it started flaking off right away.
I've heard more bad stories than good.  A lot of people say the part will still rust under the coating.  A lot of people have said that it flaked off in a short amount of time even after following the instructions to the letter.  IMO it is marketed to the people who want a quick fix and who don't want to fix rust the proper way.  Basically every part that I had coated, I stripped and redid.  The only POR product that I do like is the POR-Strip.  It works great at removing the dried POR coating.

 
Get rid of the rust on the floor and paint it with an automotive paint...not some gimmicky product.   

[Racer57]

I'm planning on pulling out my carpet this winter and putting something under it to insulate from heat, probably dynamat.  Is there a problem with getting the carpet to lay properly again ?

[roadman5312]

Racer57, I use dynamat on all the cars I work on, causes no problems with carpet installation. Just make sure you trim out all bolt/screw holes before hand.