E-coating/Rustproofing/Priming

[Keith the Rocket]

Hi ... I am nearing the painting stage of my TR4 rebuild and I've been considering to option to have the body tub & outer panels  dipped and primed and possibly e-coated.... 

Does anyone have experience of this and do the benefits justify the costs..   

Apart from the outer visible area's which will likely need further preparation to get the pefect finish, once primed and e-coated, it normal practice to simply apply paint straight to the body... in particular the inner and bottom (unseen) areas, or are other processes required?

Thanks

Keith

[stuart]

I used to have this done but have veered away from it due to possible problems further down the line with chemicals leeching from seams. Ive gone back to sand blasting as its a known quantity, obviously not for unsupported panels . Then coating with Bondarust primer and then 2k primer/Top coat. Underneath its Bondarust then stone chip then 2k primer/Topcoat.

Stuart.

[TR4Tony VC]

I’ve had a series of bodytubs, panels and chassis pyrostripped recently and had the choice of coating in an etch primer, a weld through primer or a direct e coat. 
 

Etch primer needs to come off to get on with welding but lasts longer after application. Good for a job that takes a while and you can get on with bit by bit. Weld through is light and porous, so won’t stay good for long so great if the job is good with little more to do, or needs match repair and a lots of the primed panels will be cut or replaced / repaired in a short time - this is what I’ve found preferable.

 

The advice that I had one e coat (from someone who owned a coating business) is that it’s fine if the surface and joints, seams etc as Stuart has highlighted above are perfect and detritus free, but if you have to do any post coating works at all, the coating is compromised and needs repair, so it very quickly loses the advantage over a good wet painted primer and undercoat. An e coat can also be scratched or sanded away during prep for paint, again losing the protection that you would hope for.

Photos below are are of a pyrostripped shell in weld through primer.

regards

Tony

[PodOne]

I considered dipping and looked into it but came across too many stories of subsequent leaching ruining the paint.

So took Stuart's advice and after doing all the repairs had the tub blasted along with the panel edges. The tub was then coated with Bonda rust and any lead work done, more Bonda rust and then painted with 2K truck chassis primer and then seam sealed. The panels were all bare metalled, repaired, leaded and then two coats of Bonda rust. Fitted panels and adjusted with the tub bolted to the chassis. Bonda rust was pored into the sills and sloshed until some of it was seen running out of seams perhaps overkill but that me.

The tub then had body coloured tinted Raptor applied underneath to floor pan and wheel arches etc and inside eg boot etc. Long, long job but hopefully worth it. Lots of extra holes/bungs made to access sills and B posts etc to allow repeated wax injection.

Blasting cheaper but find a man who is used to blasting car shells.

Andy

[TR4Tony VC]

On 9/6/2024 at 10:12 PM, PodOne said:

I considered dipping and looked into it but came across too many stories of subsequent leaching ruining the paint.

So took Stuart's advice and after doing all the repairs had the tub blasted along with the panel edges. The tub was then coated with Bonda rust and any lead work done, more Bonda rust and then painted with 2K truck chassis primer and then seam sealed. The panels were all bare metalled, repaired, leaded and then two coats of Bonda rust. Fitted panels and adjusted with the tub bolted to the chassis. Bonda rust was pored into the sills and sloshed until some of it was seen running out of seams perhaps overkill but that me.

The tub then had body coloured tinted Raptor applied underneath to floor pan and wheel arches etc and inside eg boot etc. Long, long job but hopefully worth it. Lots of extra holes/bungs made to access sills and B posts etc to allow repeated wax injection.

Blasting cheaper but find a man who is used to blasting car shells.

Andy

Dipping is indeed fraught for TR’s because if the way the body tubs are made … with seams and overlaps all over the place. Pyrostripping at low temperature is in my experience much better, but I still found that I had to open seams up and rust proof, reprise and in all cases seal the seams up.

I think the BondaRust idea is very good and honestly no amount of rust protection I can be over the top !

[Waldi]

9 hours ago, TR4Tony VC said:

…….Pyrostripping at low temperature is in my experience much better, …..

Hi Tony,

what do you consider a low temperature for pyrostripping?

Thanks,

Waldi

[roy53]

I did contact the company that Pete Felon used [ Ribble tec i believe ] and they no longer do body tubs.

Is there anywhere else that dose this ?

Roy

[TR4Tony VC]

16 hours ago, roy53 said:

I did contact the company that Pete Felon used [ Ribble tec i believe ] and they no longer do body tubs.

Is there anywhere else that dose this ?

Roy

Envirostrip in Tamworth do body tubs and chassis 

[Motorsport Mickey]

On 9/7/2024 at 10:23 PM, TR4Tony VC said:

Dipping is indeed fraught for TR’s because if the way the body tubs are made … with seams and overlaps all over the place. Pyrostripping at low temperature is in my experience much better, but I still found that I had to open seams up and rust proof, reprise and in all cases seal the seams up.

I think the BondaRust idea is very good and honestly no amount of rust protection I can be over the top !

That sounds very comprehensive Tony, what rust proof system do you use to kill the rust ?  is it a chemical phosphoric acid based, or do you use a rust converter system ? 

Mick Richards

[roy53]

8 hours ago, TR4Tony VC said:

Envirostrip in Tamworth do body tubs and chassis 

Are they not acid not the heat system?

[stuart]

1 hour ago, roy53 said:

Are they not acid not the heat system?

They do the heat then acid dip, Ive had a couple of shells done there but what I found was all the paint/filler debris after the dip collected in the box sections and in between seams. Luckily both of them I had to nigh on dismantle the whole shell to repair anyway so cleared it all out but I dont know how inert that would be in the long run if left.

Stuart.

 

[David Farmery]

Definitely try Envirostrip.

No chemicals, no blasting, choice of primer. 

I had my shell and various other second hand panels treated, never a problem.

[stuart]

47 minutes ago, David Farmery said:

Definitely try Envirostrip.

No chemicals, no blasting, choice of primer. 

I had my shell and various other second hand panels treated, never a problem.

They certainly do use chemicals.

Stuart.

[TR4Tony VC]

13 hours ago, Motorsport Mickey said:

That sounds very comprehensive Tony, what rust proof system do you use to kill the rust ?  is it a chemical phosphoric acid based, or do you use a rust converter system ? 

Mick Richards

Hi Mick

Firstly I open up the seams as best I can before the shell goes off, that helps.

Secondly, when I’ve cleaned any debris out I use a phosphate rust proofer - Kurust is very similar and thin enough to seem into seams etc. The gel types are too thick and leave an uneven residue, penetrate less well and also form their own debris when they cure.

Regards

Tony 

[TR4Tony VC]

11 hours ago, stuart said:

They do the heat then acid dip, Ive had a couple of shells done there but what I found was all the paint/filler debris after the dip collected in the box sections and in between seams. Luckily both of them I had to nigh on dismantle the whole shell to repair anyway so cleared it all out but I dont know how inert that would be in the long run if left.

Stuart.

 

I found similar inside a chassis in various places and had to hook it all out with a long rod and a wood chisel.

[stuart]

12 hours ago, TR4Tony VC said:

I found similar inside a chassis in various places and had to hook it all out with a long rod and a wood chisel.

Problem is whether that debris is still holding any chemicals from the dip and whether in future any water ingress would then leach it out as your never going to be able to open all of the enclosed box/panel sections to be able to get it all out.

Stuart.

[John Morrison]

Following on from the wisdom imparted here.

Two quick questions, can you put a blocking coat of fillerover keyed Bondarust,

and does anyone have a recommendation for which filler to buy/or not to buy?
John.

[stuart]

21 minutes ago, John Morrison said:

Following on from the wisdom imparted here.

Two quick questions, can you put a blocking coat of fillerover keyed Bondarust,

and does anyone have a recommendation for which filler to buy/or not to buy?
John.

Yes you can, its what I do, I stick with UPOL products, I use UPOL D for main filler and their EPOXY 3 for fine finishing.

Stuart.

 

[John L]

Wouldn't this be a good topic to be saved/locked, it covers a great deal of questions with very suitable answers on body preparation,  would the moderators agree please?

John

[John Morrison]

Yes John, very useful subject.

I have ammended the title to include, rustproofing and priming.

and pinned the topic.

John.

[dave bailey]

Hi. There's some really good information going on here. I'm trying to sort out how I'm going to tackle the job in the near future.

I'm currently rebuilding my TR5 bodyshell after major surgery, involving cutting in half and removing quite a few panels that were distorted and/or rusted, ( including the boot floor and side panels which were in aluminium (anyone got a use for these panels?).

So most of the paint/sealants and general gunk have been removed in the process, but I'd still like to have the tub blasted anyway to give myself a consistent  surface finish.

This then brings me to what to do next. So my scheme at the moment is as follows.

1) Complete repair/rebuild of tub.

2) Have the tub blasted. (I don't want to use chemical stripping.)

3)Then:- Choice A. Coat in Two pack epoxy primer.

                                 Use filler / lead loading wherever necessary.

                                  Coat in Bondaprimer.

                Choice B. Coat in Bondaprimer.

                                  Use filler/ lead loading wherever necessary.

                                  Coat in Two pack epoxy primer.

(Or don't use Bondaprimer at all.)

There seems to be various options about post blasting treatment and I would appreciate any thoughts on my scheme, or any other ideas.

Dave.

[TR4Tony VC]

Hi Dave

I think using a weld thru primer like NOVOL works well as you don’t have to remove it to weld in repairs. Bondaprimer is very good, but you need to get it off to weld reasonably, so I’d say put that on after repairing so that there is a good coat of primer on there. NOVOL (as most etc primers I think) is very porous, so metal will go off eventually.

Regards

Tony 

[stuart]

1 hour ago, dave bailey said:

Hi. There's some really good information going on here. I'm trying to sort out how I'm going to tackle the job in the near future.

I'm currently rebuilding my TR5 bodyshell after major surgery, involving cutting in half and removing quite a few panels that were distorted and/or rusted, ( including the boot floor and side panels which were in aluminium (anyone got a use for these panels?).

So most of the paint/sealants and general gunk have been removed in the process, but I'd still like to have the tub blasted anyway to give myself a consistent  surface finish.

This then brings me to what to do next. So my scheme at the moment is as follows.

1) Complete repair/rebuild of tub.

2) Have the tub blasted. (I don't want to use chemical stripping.)

3)Then:- Choice A. Coat in Two pack epoxy primer.

                                 Use filler / lead loading wherever necessary.

                                  Coat in Bondaprimer.

                Choice B. Coat in Bondaprimer.

                                  Use filler/ lead loading wherever necessary.

                                  Coat in Two pack epoxy primer.

(Or don't use Bondaprimer at all.)

There seems to be various options about post blasting treatment and I would appreciate any thoughts on my scheme, or any other ideas.

Dave.

Option B is what I do, that way it doesnt matter how long it takes to do the job as Bondaprime will protect whereas the other things like etch primer dont. Its easy enough to clean up where your going to weld as you`ll only need to clean an edge. Bondarust is quite heat resistant and only goes brown when you weld right up to it so its also good for internals of new panels that are getting welded on like sills etc. FWIW any weld thru primer isnt very good for MIG repairs but fine for spot welding ones.

Stuart.

[dave bailey]

Hi. There's some really good information going on here. I'm trying to sort out how I'm going to tackle the job in the near future.

I'm currently rebuilding my TR5 bodyshell after major surgery, involving cutting in half and removing quite a few panels that were distorted and/or rusted, ( including the boot floor and side panels which were in aluminium (anyone got a use for these panels?).

So most of the paint/sealants and general gunk have been removed in the process, but I'd still like to have the tub blasted anyway to give myself a consistent  surface finish.

This then brings me to what to do next. So my scheme at the moment is as follows.

1) Complete repair/rebuild of tub.

2) Have the tub blasted. (I don't want to use chemical stripping.)

3)Then:- Choice A. Coat in Two pack epoxy primer.

                                 Use filler / lead loading wherever necessary.

                                  Coat in Bondaprimer.

                Choice B. Coat in Bondaprimer.

                                  Use filler/ lead loading wherever necessary.

                                  Coat in Two pack epoxy primer.

(Or don't use Bondaprimer at all.)

There seems to be various options about post blasting treatment and I would appreciate any thoughts on my scheme, or any other ideas.

Dave.

[dave bailey]

Hi. Thanks for the reply, (sorry, seem to have posted the post again, don't know why!)

Anyway, I agree Stuart, that option B is favorite, although I've heard that two pack epoxy primer should be applied directly to bare metal, just wondering how it would fare on top of Bondaprimer (a product I have never used)

Dave.