Advice on stripping pads for underneath

[Jim881]

Hi all,
I am in the process of treating the underside of my celica. I've just ordered a needle scaler (cp7115) and am wanting to get some pads to prep the surface prior to applying Jotun 90.
I've been looking at the norton rapid strip pads for my air grinder and the 3m ones 50mm & 75mm (Running a 2.5hp SGS compressor)
Can anyone recommend what I should buy to do the job? Included some pictures of the suspension I have already done and what the area is like under the car pre me removing the fuel tank etc.

 

[a111r]

Good work! Those things are noisy as hell...
See that fuel tank is glaring at you, to buy, variously:
A roller over jig / a garage / multiple crates of wine for the neighbours / some psychotherapy.
Good luck in your quest.

 

[eddie49]

Hello and welcome!
I have been doing a similar job, removing rust from under a 2012 Peugeot iOn EV. Apart from the usual variable speed angle grinder, flap discs, strip discs, nylon filament rotary brush, and Roloc discs, I have found that the most useful tool is a finger sander/mini belt sander/powerfile.

 

[Ross365]

I rely very heavily on my Bosch angle grinder with wire brushes and a mains drill + wire brush. The latter can be used with one of those flexible extension drive cables+chuck. Don't often use much else... except some PPE!

 

[Jim881]

Good work! Those things are noisy as hell...
See that fuel tank is glaring at you, to buy, variously:
A roller over jig / a garage / multiple crates of wine for the neighbours / some psychotherapy.
Good luck in your quest.

Thanks, yes I have seen they can be pretty noisy!! I have saved myself some work with the fuel tank. Manged to source a genuine one from abroad with no rust so I stripped it back last week and i can just paint that. I would love do do the whole underneath on a jig but unfortunately don't have the space. My plan is to don't the back half now and the front at a later date.

 

[Jim881]

Hello and welcome!
I have been doing a similar job, removing rust from under a 2012 Peugeot iOn EV. Apart from the usual variable speed angle grinder, flap discs, strip discs, nylon filament rotary brush, and Roloc discs, I have found that the most useful tool is a finger sander/mini belt sander/powerfile.

Hi and thank you,
I looked at the variable speed angle grinder but they were bloody expensive so decided to get a small 90 degree die grinder. It works well, not as powerful as a electric angle grinder but easier to hold abovey head for long periods. Can I ask what brushes and rolocs you bought?

 

[Jim881]

For me its the angle grinder with stainless steel wire brushes and good goggles, removes most things and the brushes can be washed out.

Thanks, I'll have a look at some stainless steel attachments. I've already got a mask and a good pair on goggles. Learnt my lesson a few years ago and ended up in hospital to get metal removed from my eye!!!

 

[Dcal]

You can strip most of the under seal off with a sharp wood chisel, then as said, finish it off with wire brushes in a grinder / drill.
A needle scaler is great for heavy rust on suspension components and the like but will damage thin metal if you are not careful.
Just a heads up if you don’t already know, the tank looks far too shiny for the Jotun, give it all a good sanding with 80 or 120 sand paper before painting and you will get great results.
There are plenty of examples of similar work a few of us have done in the project pages, so well worth a look.

O and welcome to the forum, you should start a build thread on your Celica.
Sounds like a great project and well worth doing.

 

[tom2207]

A hot air gun is handy on seam sealer ,, with an old wallpaper .[ not woodchip] scraper ,,,
but fot the want of sounding a tad obvious
be careful those things are not a heavy duty hairdryer they are more like a flame-less blow torch
they get HOT HOT HOT.
as in set things on fire on the inside , melt the trim hot.

 

[Jim881]

You can strip most of the under seal off with a sharp wood chisel, then as said, finish it off with wire brushes in a grinder / drill.
A needle scaler is great for heavy rust on suspension components and the like but will damage thin metal if you are not careful.
Just a heads up if you don’t already know, the tank looks far too shiny for the Jotun, give it all a good sanding with 80 or 120 sand paper before painting and you will get great results.
There are plenty of examples of similar work a few of us have done in the project pages, so well worth a look.

O and welcome to the forum, you should start a build thread on your Celica.
Sounds like a great project and well worth doing.

Thanks for the welcome. She is a labour of love and will never get sold. Did the engine bay a year or so ago. The underside needs my attention now. I not doing things by half and have sourced new nuts and bolts as well as stuff to refurb.
Yeah the tank has already been keyed as I did read jotun doesn't like a smooth finish.
The needle scaler is for the heavily rusted areas. I was hoping it would take the underseal off as well? My plan was to use the needle scaler, followed buy some steel wire brush attachments then some roloc ceramic pads. Don't think sounds like a decent plan?

 

[Jim881]

A hot air gun is handy on seam sealer ,, with an old wallpaper .[ not woodchip] scraper ,,,
but fot the want of sounding a tad obvious
be careful those things are not a heavy duty hairdryer they are more like a flame-less blow torch
they get HOT HOT HOT.
as in set things on fire on the inside , melt the trim hot.

I have a hot air gun in the garage and they do get bloody hot!!! I've stripped the rear already to treat some rust around the wheels arches so they will be safe.

 

[Dcal]

The needle scaler won't be much use on underseal, even grit blasting is hopeless.
There are better quicker ways as stated above.

 

[Jim881]

Its the bristles I would be worried about as some do fly out and stick everywhere.

Been there mate. Used a knotted wheel to clean a railing with and angle grinder in shorts.....

 

[charlysays]

I am in the middle of a similar job mate... dropped the rear subframe off my Merc C250 TD. Discovered loads of rust and a few very small holes.
I got everything removable shot blasted, rinsed it with brake cleaner then painted with 2 coats of bilt hamber epoxy mastic. Ofcourse all the bushes were knackered, mostly due to galvanic corrosion between differing metals rather than wear so its having all new bushes/ arms and mountings.
Under the car I've been using a needle scaler too- mine is a kobe but basically the same as the small one from CP tools.

You won't damage the metal if you keep the needles at an angle to it. I've used the needle scaler on our panels without causing any denting. When they lose their edge you can grind them square again on a bench grinder without removing from the scaler. I find the needle scaler excellent at removing loose underseal and getting rid of most of the bulk of the corrosion including in craters but as said it will be of limited use if you want to strip lots of intact underseal.

I use a silverline right angle air drill with straight bristle wire wheels which gets an extremely clean looking bright shiny surface following needle scaling. With a good going over with 60 grit I think it would meet the required St.2 prep standard. I think fracturing up the corrosion with the needle scaler allows the wire wheels to be far more effective.

I have a cheapo mini air DA which I'll be using with 60g oxide pads then doing the rest / corners etc by hand.

Depending how it looks after i've needle scaled and wire wheeled it all I might go over it with scaleX rust remover too but still a bit undecided.

As a side note... whats the best way of getting jotun 90A out of the massive 5l can for smaller jobs? I'm considering decanting into a cleaned out 2.5 paint tin tbh as it could end up getting very messy.

 

[Fastdruid]

One technique I've heard of but never tried myself is using dry ice. Either to supercool it down (and then it cracks off with a hammer etc) or as a blasting media.

 

[Roger440]

If the underseal is dry and flakey, the needle scaler will have it off.

But is it really underseal, as in bitumen based. Or is it some polyurethane stle sealer?

 

[Jim881]

I am in the middle of a similar job mate... dropped the rear subframe off my Merc C250 TD. Discovered loads of rust and a few very small holes.
I got everything removable shot blasted, rinsed it with brake cleaner then painted with 2 coats of bilt hamber epoxy mastic. Ofcourse all the bushes were knackered, mostly due to galvanic corrosion between differing metals rather than wear so its having all new bushes/ arms and mountings.
Under the car I've been using a needle scaler too- mine is a kobe but basically the same as the small one from CP tools.

You won't damage the metal if you keep the needles at an angle to it. I've used the needle scaler on our panels without causing any denting. When they lose their edge you can grind them square again on a bench grinder without removing from the scaler. I find the needle scaler excellent at removing loose underseal and getting rid of most of the bulk of the corrosion including in craters but as said it will be of limited use if you want to strip lots of intact underseal.

I use a silverline right angle air drill with straight bristle wire wheels which gets an extremely clean looking bright shiny surface following needle scaling. With a good going over with 60 grit I think it would meet the required St.2 prep standard. I think fracturing up the corrosion with the needle scaler allows the wire wheels to be far more effective.

I have a cheapo mini air DA which I'll be using with 60g oxide pads then doing the rest / corners etc by hand.

Depending how it looks after i've needle scaled and wire wheeled it all I might go over it with scaleX rust remover too but still a bit undecided.

As a side note... whats the best way of getting jotun 90A out of the massive 5l can for smaller jobs? I'm considering decanting into a cleaned out 2.5 paint tin tbh as it could end up getting very messy.

Thanks mate, very informative. I've got some 3m pads as well as the norton blaze pads to prep the surface well. I'm not sure the condition of the underseal yet. I know some bits are loose so hopefully the needle scaler will take this off easily enough. Going to need to decant mine as well. I shall just be making up a litre at a time.

 

[Jim881]

If the underseal is dry and flakey, the needle scaler will have it off.

But is it really underseal, as in bitumen based. Or is it some polyurethane stle sealer?

Think its bitumen based mate. The stuff I removed from the wheel well and under the rear seats was all bitumen.

 

[Roger440]

Think its bitumen based mate. The stuff I removed from the wheel well and under the rear seats was all bitumen.

In that case, spray disel on it, leave a couple of days and then wipe off and clean with brake cleaner..