Small rust hole in drivers side sill

[BongoBongo123]

Was checking the Bongo over for rust and about 15 inches forward from the drivers side rear arch there was a rusty bubbling spot. I took the plunge and screw drivered it. It went through. Fearing the worst I went along the sill scraping and prodding the slightly rusty areas. Bit annoying as I keep on top of this kind of thing but I guess when it goes from the inside out you only know when you see a bubble.

Luck has it (looking on the bright side of having a hole that is) that the hole is the only one. In that it came from the inside out. The others all appear to the eye to be surface rust. A bit of scraping reveals clean shiny metal. Phew ! Temporarily touched them up with Hammerite just for a few days/ weeks.

I plan getting a patch welded over the hole. I have squirted as much Jenolite fluid into the area as was practical this morning it is dripping out and drying up. In theory that should toughen up the interior around that spot for now. I held off on the Waxoyl as if welding is to take place I don't want it catching fire/causing problems for the welding guy. The hole is 2cms by 1cm on the sill ledge that is horizontal to the ground. (This is pic is just before I broke through it with the screwdriver so it is a bit bigger than this shows)



I am going to the local garage to show them the hole and get them to patch it.

I spoke to Ian from the forum fearing initially thinking that the sill might need replacing but it seems that might probably won't be required. He mentioned around that area there is an air con compressor and this can remain damp and that it is likely that it was used in humid conditions in Japan and this can be a weak spot for rust in the sill. So with this knowledge maybe check yours out asap.

I plan to get the hole welded and then go along the sill and sand it down Kurust it and then either Hammerite or POR15 it along.

So, I am disappointed for all my efforts keeping an eye on things that it has a hole but in reality there is nothing I could really do anyway given it was eaten through from the inside out. Fairly sure that all the other spots are just surface rust spots on the outside.

And to the point...

Once the hole is welded I want to get Waxoyl in but the drivers side of the Bongo does not have any grommet holes to get it in the sill (the passenger side does). So is the only option drilling 3mm holes in and then filling them after spraying a tonne of waxoyl in ? I cannot seem to find any other rubber blanking grommets than about 10mm in size. I do not really want to drill holes of that size in the sill if I can help it. After all how is a hole like that any less of an MOT fail than a rust hole ?

[Bob]

You could use self tappers to fill a 3mm hole, easy to remove if you want to top up, too.

[BongoBongo123]

Not a bad idea bob and grease the hole and screw over for good measure.

I guess catching this early before that hole ate its way along is still a good thing it could be a hell of a lot worse. Right time to sort it out as well before the wet months appear.

[Bongolia]

Bongobongo123
I would be inclined to sight the access holes vertically on the inner sill rather than under the outer "sill" panel and keep the number to a minimum consistent with a proper job.
Drilling of holes 10mm in that instance would be fine and would give better access with the lance but you should be able to get blanking grommets of varying sizes from a motor factors or Amazon/Ebay.

If memory serves me correctly the passenger side inner sill panel on my Bongo has several "grommets" I don`t know whether these were from a previous injection process but they are larger than 10mm and I passed mine.

The test criteria relates to corrosion within a prescribed area or on supporting panels, arguably the outer panel of the "sill" is just a closing panel the supporting structure would be the riser plate sandwiched between the inner sill and the outer closing panel.
Minor mods like you propose would not be deemed as weakening the structure so it would not fall under the deliberate modification criteria.

https://mot-testing.i-env.net/documents ... 000001.htm

[mikeonb4c]

I fear you must expect (but not get down about) rust. From memory i have had (on a pretty smart looking Bongo) plates welded at both front cross member junctions; both sill front ends inside front wheel arches; one section on n/s cill half way down length; around rear heater; rear cross member up behind exhaust heat shield; n/s/r inner wheel arch and bumper mounting area/bracket; n/s/r sill end; complete new cross member underneath radiator; new metal pipe to rear heater due to corrosiin failure. I'm inclined not to believe anyone who sells an ageing Bongo with a long uk life and who claims it is rust free: more likely is they've not gone looking for it! Its a good feeling to know that i now really do have a substantially rust free Bongo.....until the next discovery. But i think there are some classic problem areas that, once fixed, should not cause trouble again for many years. And my welder uses steel twice as thick as original sheet.

[BongoBongo123]

That has calmed me down a bit Mike thanks ! Puts it in perspective and glad I found it now. I will simply gaffer over the hole now to stop water ingress/spray till I sort the welding.

Bongolia.. thanks for that info and clarification so you suggest there are some holes that I can squirt Waxoyl in further under and behind the sill... i.e. right under and behind on the vertical rear sill wall ?

A matter of donning the latex gloves and feeling around for holes behind/up and under ?

[Bob]

Sounds like a game of 'Customs Officers and Drug Smugglers'.

[BongoBongo123]

Ok I found 4 x vertical grommets up and under the sill (drivers side)but all starting from the driver door forwards to the front of the vehicle. 4 grommets but all under the driver door area.

And hats off to Ian.. this rust hole is EXACTLY where an aircon pump is can see the 2 rubber pipes connected via some kind of squarish alloy connectors), good knowledge that ! So this seems to be a known weak spot. I do wonder if I can get the waxoyl to run down into the rear sill where there is no grommets or access holes at all on either horizontal or vertical surfaces. Maybe on a hill with it leaning backwards.

I think I would only be sure it would have good coverage with the drill and fill method.

Shame there are not more access holes in the sill that actually needed it ! None along the rear driver side and plenty on the passenger side. The passenger sill is rock solid.

[BongoBongo123]

I will use Waxoyl aerosol cans with the little tube insert. Maybe a bit more expensive but it is the only way I can get it in 3mm holes. (Maybe not that expensive as the Waxoyl pump is £24.00) 4 cans should do it I can get them for about £24.00

An almost 1L can of POR15 is £39.00 it seems ridiculously expensive for paint but it seems like this stuff is the ultimate rust inhibiter seal.

At least I have a plan of attack now.

[mikeonb4c]

That has calmed me down a bit Mike thanks ! Puts it in perspective and glad I found it now. I will simply gaffer over the hole now to stop water ingress/spray till I sort the welding.

Bongolia.. thanks for that info and clarification so you suggest there are some holes that I can squirt Waxoyl in further under and behind the sill... i.e. right under and behind on the vertical rear sill wall ?

A matter of donning the latex gloves and feeling around for holes behind/up and under ?

Don't waxoyl if you're going to be welding soon. I find glasscloth tape and Dinitrol make an excellent weatherproof patch for non structural holes.

I had to have welding around my rear heater unit. With skill and luck they managed to do it without removing the unit, which saved a lot on labour cost.

[BongoBongo123]

Sure Mike, sage advice. I have temp gaffered over the hole it will fine for a few days I suspect. (which I sprayed through into the sill with copious amounts of Jenolite yesterday) and this will be fine just till mid next week when I get the welder to check it/sort it. The plan is to get the hole patch welded first. Then drill and fill with Waxoyl, sort out the surface rust with KURUST and then POR15 and possibly Hammerite top coat. Might forego the Hammerite top coat and go for 2 POR15 grey layers. No one sees under that lip/shelf it down there anyway really.

[Bongolia]

I wish you hadnt mentioned latex and groping.

[BongoBongo123]

Playing on ones mind.

Anyway gone for POR15 £35.50 for 1L and 4 aerosol cans Waxoyl. 4mm hole and 4.2mm self tappers (16mm long) All my bits on their way so they will be ready for post welding anti rust job.

That POR15 anti rust paint is supposedly the best stuff since sliced bread, here is to hoping.

[mikeonb4c]

Playing on ones mind.

Anyway gone for POR15 £35.50 for 1L and 4 aerosol cans Waxoyl. 4mm hole and 4.2mm self tappers (16mm long) All my bits on their way so they will be ready for post welding anti rust job.

That POR15 anti rust paint is supposedly the best stuff since sliced bread, here is to hoping.

I tried sliced bread on rust holes. Cheap but it didn't work very well. Toast was better, until it got wet

[BongoBongo123]

I imagine always better lashings of butter on, unsalted mind you !