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Rear sub frame swap - off for galvanzing, may turn into a project thread


rider

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People will have noted from my underneath what parts needed thread that this is an impending job on my Supra. I obtained a replacement frame last year that was supposed to have been treated and powder coated. Having stripped the hubs and arms off yesterday I tackled some bubbles with a grinder on the frame and found it is literally covered in surface rust. Thankfully nothing that is heavily pitted below the very thick layer (over 1mm) of high build primer and silver paint top coat. There are clearly parts on a rear frame that no grinder or sanding can reach so I'm taking it off to Surface Processing in Dudley on Monday to have it acid stripped and then an electro treated coating as its going to be virtually impossible to get a proper paint covering into the closed sections within the frame. I'll fill those with thinned down primer and finish up the closed sections with Dinitrol spray after I have applied the final spray paint cover to the frame.

 

Cost of the treatment is £165 + VAT. I'll post up pics of the frame when I get it back from Surface Processing and the final ready to fit frame after I have finished paining it. It's extra cash I was hoping I wouldn't have to spend but at least I'll know its all be done properly which clearly didn't quite happen with this frame when it was last refurbished.

 

I have employed a mechanic to double up on frame swap over with me pencilled in start time mid September with put back together planned for around November to give time for any replacement parts and bushes to be sourced and the underneath bodywork to be cleaned, primed and painted. also swapping at the same time the tank guard (with new), front to rear fuel and brake lines and the exhaust .

 

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People will have noted from my underneath what parts needed thread that this is an impending job on my Supra. I obtained a replacement frame last year that was supposed to have been treated and powder coated. Having stripped the hubs and arms off yesterday I tackled some bubbles with a grinder on the frame and found it is literally covered in surface rust. Thankfully nothing that is heavily pitted below the very thick layer (over 1mm) of high build primer and silver paint top coat. There are clearly parts on a rear frame that no grinder or sanding can reach so I'm taking it off to Surface Processing in Dudley on Monday to have it acid stripped and then an electro treated coating as its going to be virtually impossible to get a proper paint covering into the closed sections within the frame. I'll fill those with thinned down primer and finish up the closed sections with Dinitrol spray after I have applied the final spray paint cover to the frame.

 

Cost of the treatment is £165 + VAT. I'll post up pics of the frame when I get it back from Surface Processing and the final ready to fit frame after I have finished paining it. It's extra cash I was hoping I wouldn't have to spend but at least I'll know its all be done properly which clearly didn't quite happen with this frame when it was last refurbished.

 

I have employed a mechanic to double up on frame swap over with me pencilled in start time mid September with put back together planned for around November to give time for any replacement parts and bushes to be sourced and the underneath bodywork to be cleaned, primed and painted. also swapping at the same time the tank guard (with new), front to rear fuel and brake lines and the exhaust (Nur R).

 

I did warn you about the condition of them if you remember?

They had simply powder coated over rust, my rear exhaust heat shield was the same off the same car that has now been acid dipped and shot blasted too!

I would check everything on them bushes et. as the car was cobbled together I remember him saying some thing about the wheel bearings not been fitted correctly too.

It will all come out good in the end although the pitting where the rust was will still be evident that's why I am fitting a corrosion free on to my red uk tt6 when I get round to it!

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I did warn you about the condition of them if you remember?

 

You did indeed.

 

The front frame I bought at the same time is good, as you would expect seeing it sees less debris than the rear. I was planning on using the links, hubs and arms from the rear frame I bought off Mike but the ball joints on them are all bodged and the purple replacement bushes seem very soft. No wonder that car got scrapped, it looks like it could have been one massive bodge. Still, looking on the bright side of life it only appears at this stage to be a major dose of surface rust so I'm hoping the frame will come out the proper refurb side looking pretty close to new.

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You did indeed.

 

The front frame I bought at the same time is good, as you would expect seeing it sees less debris than the rear. I was planning on using the links, hubs and arms from the rear frame I bought off Mike but the ball joints on them are all bodged and the purple replacement bushes seem very soft. No wonder that car got scrapped, it looks like it could have been one massive bodge. Still, looking on the bright side of life it only appears at this stage to be a major dose of surface rust so I'm hoping the frame will come out the proper refurb side looking pretty close to new.

 

Yes the fronts seem pretty good although Keron warned me about them rusting through so I have a spare just incase.

The rears are extremely tough I haven't heard of a rear one rusting though its more cosmetic than anything.

I must admit some parts I have bought could have been more honestly described I think I am a little too critical on my own items when selling things like the UK calipers I have listed atm.

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I haven't heard of a rear one rusting though its more cosmetic than anything.

 

I'm sure the frame on my car would pass its MOT for at least another 20 years but whipping it off lets me tackle the rusting brake and fuel lines that won't last another 20 years and also to have a good poke around the bodywork under the car that you wouldn't normally get to with the fuel tank, exhaust and frame in place. Seeing the car only does 1,000 miles a year now and lives indoors in my dehumidified garage I'm hoping what gets done now stays done for pretty much ever as far as my lifetime is concerned.

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Acid dip is the correct way. When I refurbed my rear subframe I spent an annoying amount of time with a grinder getting it as clean as possible, but there are still nooks and crannies that are impossible to get to with a tool or even a sand blaster.

 

My thoughts were to do a dip of some sort when I go to refurbish sometime again in the future, and for the money acid dip seems like a good option. Interested to see how it comes out.

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My chassis had to be hot zinc dipped 3 times to remove all corrosion and slag from the inside of the frame. Each time

the zinc was removed with hydrochloric acid taking a bit more of the slag and corrosion away until on the 3rd dip it came out

perfect

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I'd take it to Howells in Wolverhampton and get stripped the zinc coated, they did my RRC chassis, that treats

the inside the same as the outside as long as there is holes on the frame to let the zinc and out of

 

Top tip. Talked to Edward Howells and they don't do the stripping stage but recommended Bevlyn for that. So now dropping off the frame to Bevlyn on Monday for a oven paint strip and Howells will collect from there and do the pickling and galvanizing. Total cost £120 plus VAT. I wonder how many Supras there are out there running on galvanized frames?

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Top tip. Talked to Edward Howells and they don't do the stripping stage but recommended Bevlyn for that. So now dropping off the frame to Bevlyn on Monday for a oven paint strip and Howells will collect from there and do the pickling and galvanizing. Total cost £120 plus VAT. I wonder how many Supras there are out there running on galvanized frames?

 

Only yours i'd imagine

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Nice move going for the galvanised :thumbs: Giving me a lot of ideas and food for thought for when I eventually tackle my subframes.

 

Seeing the car only does 1,000 miles a year now and lives indoors in my dehumidified garage I'm hoping what gets done now stays done for pretty much ever as far as my lifetime is concerned.

 

Get out there and drive it! It's only an old Toyota at the end of the day lol

 

Being serious though, I had a similar conversation with a close friend and club member lunchtime about this very subject of putting cars away and not wanting to drive them. I personally really really hope that this isn't the way the car club goes with owners being too precious over them and scared to drive them with the fear they will put miles on the car!

 

As you know I'm in for the long haul with mine for the next 20 to 30 years, and it will continue to have a no expense spared restoration along the way, with everything I can replaced for new, but that in no way means I won't drive it! It's been done for the very reason for me to be able to beat it to death on Dragonball once or twice a year, and all over the UK, I won't have a single hesitation about putting over a 1000 miles on it for a DB trip. I really hope that we never see the end to long European trips being organised and members willing to push the cars and drive them hard and put the miles on. I just think its sad to keep them as garage ornaments in the hope they will increase in value.

 

If the club did go down the road of a classic car club with owners not wanting to put miles on, I'd seriously have to consider getting a GTR or Porsche for a daily and fun car, and to join a club with active Euro driving trips etc... Sports cars are meant to be driven!

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I personally really really hope that this isn't the way the car club goes with owners being too precious over them and scared to drive them with the fear they will put miles on the car!

 

When you start putting money and time and effort into a car then it generally is either a pain, ready to be moved on, or something worthwhile preserving. I have driven the car for almost 90,000 miles so its not like it hasn't been driven but I see where you are coming from. I do think once the cars hit around the £50k level people will worry about taking them out knowing if some oik bashes into them its going to be hell tracking down replacement panels and plastic bits and most will end up locked away, rarely to see the light of day.

 

That doesn't stop the long haul expeditions though. The e-type folk have a Swiss run every year, think thats to commemorate the first motor show launch event? Its got to be a lot safer going on events and tours than it is venturing the local roads 100 times a year. Most traffic accidents do occur within 5 miles from home.

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As part of my car restoration I have considered having the shell dipped, but I have read a number of horror stories whereby the acid is not properly cleaned from hard to reach box sections and slowly continues to eat the metal away.

 

What can seem as a perfect solution can also end up as a total nightmare it seems.

 

I'm sure you will be fine with a reputable company who have a good track record. However, have you used a borescope to see if you have rust issues inside the box sections of the frame? I bought a borescope from Lidl for £40. I used this to inspect the box sections on my subframe. All appeared to be in very good condition so I simply had the subframe blasted, zinc primered and then powdercoated.

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As part of my car restoration I have considered having the shell dipped, but I have read a number of horror stories whereby the acid is not properly cleaned from hard to reach box sections and slowly continues to eat the metal away.

 

The sub frame has lots of holes into the enclosed section for bracket bolts so it can be easily drained. The galvanizing process is run at around 600C from memory and that would drive off any residual organics. The issues tend to be with phosphate coating which is done from solutions at low temperatures, up to 99C. I believe that is the Surface Process treatment which I elected to have originally but now its having an oven clean followed by HCl acid pickling and a zinc dip/plating.

 

Dropped the frame off this morning to Bevlyn for its oven bake. Had a long chat with one of the owners there, mainly about business and lazy people. They even want to see a picture of the finished article pre and post installation as they do a lot of Land Rover stuff, but this is the first Supra part they have seen.

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Interested to see this when done.

 

I'm discovering the joys of having to tap the bolt holes in the subframe. There's little powdercoat in them but plenty of accumulated crud..

 

I'll post the required sizes and thread pitches for you.

 

There's quite a selection of sizes and pitches.

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Good turn around time for the frame, 6 days. Picking the sub frame up on Monday from Howells. I'll post up a pic of the galvanized frame next week. I'll then be applying a 1K etch primer that I'll be gun spraying followed up by 1K acrylic black for the top coats that I have in spray cans. Then it'll be ready for a new set of OE bushes and finally fitting.

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Good turn around time for the frame, 6 days. Picking the sub frame up on Monday from Howells. I'll post up a pic of the galvanized frame next week. I'll then be applying a 1K etch primer that I'll be gun spraying followed up by 1K acrylic black for the top coats that I have in spray cans. Then it'll be ready for a new set of OE bushes and finally fitting.

 

Interested to see the pics :thumbs:

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As part of my car restoration I have considered having the shell dipped, but I have read a number of horror stories whereby the acid is not properly cleaned from hard to reach box sections and slowly continues to eat the metal away.

 

 

Surely if its acid dipped they should dip it into a neutralizing bath afterwards to remove the acid and stop the stripping process.

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Surely if its acid dipped they should dip it into a neutralizing bath afterwards to remove the acid and stop the stripping process.

 

Apparently it's not full proof. I read some horror stories on a VW camper van website and a Porsche site too when looking. Chris W first raised the issue in a thread I had some time back. I think it's fair to say it's more of a quality control issue. Unfortunately you'll only find out at a later date if the acid hasn't been removed properly.

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