Cavity wax in sills

[rossoe]

Hi

Just got hold of some Bilt Hamber S50 cavity wax, and wanted to fill the sills on my new 93 mx5 to protect them from the evil rust. however I have a couple of queries -

If there is any rust in there that needs converting first, is there anything Bilt Hamber do that can be sprayed, I have some Hydrate 80 but it seems more suitable for painting on, and I need to use something with a wand. is it best to go with something like Dinitrol RC900?

After converting the rust I'll seal it up with the S50 wax, but will this not gunk up the drain holes in the sill, or is that fairly easy to poke it all out from underneath?

[binnerboy]

have you read this ?

http://www.pistonheads.com/gassing/topic.asp?h=0&a...

seems like a good place to start

[BeirutTaxi]

Be careful with respect to trying to coat the inner sill - there is quite a large potential for accidentally blocking water channels/drain holes which will compound the problem.

Where about's are you based?

[rossoe]

I spoke to a technical representative at Bilt Hamber and he said not to worry with the rust converter first as the surface requires more prep which you obviously can't do on an internal sill, but he said the s50 product can be used directly into the sill to stop rust getting worse, and it's usually loose enough not to clog the holes, however I'll try and take extra measures to make the hole stay open, perhaps leave a wire or thin screw driver inserted during application and then remove when it's all set.

[rossoe]

I'm in Devon - my local mechanic is looking at doing a repair on the rear sill near wheel arch as there is rust coming through, he's going to cut out the dead area and weld a plate on. had a look underneath today whilst it was on the ramp and for 21 years old it looks in pretty good shape, just a bit or prep and sealing needed under the boot area.

Edited by rossoe on Sunday 10th November 00:21

[buzzer]

I think the secret to wax injection into sills on older cars is to use some really thin wax first.... I like to thin Waxoyle down 50% or more with white spirits for a first coat. At that thickness it almost atomises out of the spray head and creates a mist which goes EVERYWHERE. It soaks into any rust, and into the seams. In areas where there is no abrasion from the elements, I feel coverage is more important than thickness. I have looked into some sills on cars cars that have been done with thicker wax and its just gobbed on the inside and tends to block drain holes.

I used to use a borescope to look inside closed sections, but recently I have used one of the snake cameras which plug into your laptop and display a picture on the screen. These are great for looking inside areas where you cant normally see, the camera is only 10mm diameter and the lead is up to 3 meters long!

I used one to look inside a Lancia sill that had recently been "professionally" repaired and what I saw was not good to say the least. The centre strengthening web was missing for large sections, and the wax that had been squirted in there was just in globs, and I could see areas of bare metal and welds that were already starting to rust! I was also able to produce a video of it... the guy is currently talking to the restorer about the mess inside! Snake cameras can be had for just a few pounds on Ebay.

I have recently done inside my MX5 sills, and done the underside, its a messy job but well worth it. Again, I like the first coat on the underside to be nice and thin so it soaks into every knook and cranny, then follow this up when its dry with a thick coat. I am lucky in that I have a pressure pot that I can use to inject wax everywhere! I like Waxoyle, but I guess there are other equally good products on the market but I have used it with success for over 30 years and see no point in changing from what I know works. here are a few pictures. The one is taken with the snake camera inside a door.

[buzzer]

here is a link to a camera... pretty cheap now!

http://www.ebay.co.uk/itm/Mini-USB-Waterproof-Endo...

[rossoe]

Thanks buzzer - it's useful information