Just thought I'd share my new found wisdom from last week.

As you probably know, the tub of my car was full of holes, mainly from someone who was far too enthusiastic with a drill, rather than from rust. One of the biggest problems was with the drivers side floor, which had around a dozen holes, which were all around 10-12mm diameter.

We however worked out a way of filling them, by holding a large block of aluminum behind the hole whilst it was being filled with the welder.

So for everyone who has a load of holes to fill, this seems a good way of doing all of the larger holes, without having to cut out the panel and start from scratch.

Hope this is a bit of help, I know it worked wonders on my car!