par
Newbe
Posts: 3
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Post by par on Nov 18, 2023 12:30:14 GMT 1
Is there anyone out there that can refurb standard exhausts, I have a couple of minor dents and would like them cleaned/blasted repair dents and painted or coated.
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Post by lcmarky on Nov 19, 2023 9:42:12 GMT 1
I don't know where you are, but Cambs Trials Centre in March offer a blasting, ceramic coating service and will tidy them up dent wise in between I believe. I was planning to take my Nikkon pipes there at some point.
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Post by donkeychomp on Nov 19, 2023 22:21:45 GMT 1
Real easy to repair stock exhausts yourself. Save a lot of money that way too.
Alex
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Post by reedpete on Nov 19, 2023 23:26:30 GMT 1
Real easy to repair stock exhausts yourself. Save a lot of money that way too. Alex Easy to fill dents… not so easy to pull/blow them out back to original… But agree … horses for courses.. you don’t have to go the whole hog, especially if the dents are after the baffles plates section as the effect on performance is negligible/none…
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Post by bezzer on Nov 20, 2023 0:10:56 GMT 1
Real easy to repair stock exhausts yourself. Save a lot of money that way too. Alex Easy to fill dents… not so easy to pull/blow them out back to original… But agree … horses for courses.. you don’t have to go the whole hog, especially if the dents are after the baffles plates section as the effect on performance is negligible/none… What is the preferred method of filling dents Pete?, I’ve often wondered what would give best results. TIA.
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Post by donkeychomp on Nov 20, 2023 0:18:03 GMT 1
I'll answer that if Peter doesn't mind. Car filler. I use Isopon stuff. And if you want a lasting paint effect, use BBQ spray, that take a while to cure and leaves a matt finish. To get the satin look spray over that with high heat lacquer. Done it loads of times and looks like new when finished.
Alex
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Post by bezzer on Nov 20, 2023 0:52:54 GMT 1
Thanks Alex, I’d imagined car filler wouldn’t stand the heat cycles involved, and presumed aluminium filler or good old fashioned brazing/fill rods would be the answer!. Good to know as filler is easy to apply and shape.
Cheers mate. Iain.
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Post by donkeychomp on Nov 20, 2023 0:55:59 GMT 1
Glad to be of help Iain. Small dents are fine with filler. Whopping great ones that will restrict the exhaust requires dent removal and that ain't easy.
Alex
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Post by JonW on Nov 20, 2023 1:49:17 GMT 1
drill hole from the back and push a bar throurgh to knock the dents out and weld up after. round the end of the bar and you'll soon get the hang of it. folds and creases are less easy of course.
JB Weld makes a decent 'filler' and is heat resistant, thats what i use. but only in the baffle section really to keep the heat on it down. Further forward fill with weld and dress back.
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Post by tony2stroke on Nov 20, 2023 11:58:33 GMT 1
There is a kit you can buy for MX exhausts, it essentially blocks both ends, 1 end has a tyre valve, you heat the dent and pump in air, the dents pop out.
Don,t know if it works on LC exhausts as they have a mesh inside the tuned length for noise reduction, may make dent harder to remove due to the thickness.
Last time I looked they were around £50 Mark.
Just a thought.
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Post by abar121 on Nov 20, 2023 12:17:18 GMT 1
There is a kit you can buy for MX exhausts, it essentially blocks both ends, 1 end has a tyre valve, you heat the dent and pump in air, the dents pop out. Don,t know if it works on LC exhausts as they have a mesh inside the tuned length for noise reduction, may make dent harder to remove due to the thickness. Last time I looked they were around £50 Mark. Just a thought. If you have a link, that would be great. I've used high temp JB weld on small dents, also filled some with MIG without issue. Not tried this stuff, looks interesting for the lower temp areas. silverhook.co.uk/Big-boy-powder-coatable-metal-filler-250ml-high-temperature
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Post by shaunthe2nd on Nov 20, 2023 12:18:06 GMT 1
I've never used car filler but have used the JB Weld stuff, which is reasonable although not brilliant as difficult to get smooth. Don't use any fillers if you intend getting the exhausts powder coated as the oven bake will bubble it. Use BBQ rattle cans as mentioned above
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Post by shaunthe2nd on Nov 20, 2023 12:19:43 GMT 1
Having said that ^^^^ I still think brazing is best solution.
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Post by tony2stroke on Nov 20, 2023 14:09:21 GMT 1
There is a kit you can buy for MX exhausts, it essentially blocks both ends, 1 end has a tyre valve, you heat the dent and pump in air, the dents pop out. Don,t know if it works on LC exhausts as they have a mesh inside the tuned length for noise reduction, may make dent harder to remove due to the thickness. Last time I looked they were around £50 Mark. Just a thought. If you have a link, that would be great. I've used high temp JB weld on small dents, also filled some with MIG without issue. Not tried this stuff, looks interesting for the lower temp areas. silverhook.co.uk/Big-boy-powder-coatable-metal-filler-250ml-high-temperatureHere you go mate, the cheapest I could find at the mo www.ebay.co.uk/itm/364371972339?_trkparms=amclksrc%3DITM%26aid%3D777008%26algo%3DPERSONAL.TOPIC%26ao%3D1%26asc%3D20230811123856%26meid%3Da6e70456c5fa4d20942ff7ca26fbd5c0%26pid%3D101770%26rk%3D1%26rkt%3D1%26itm%3D364371972339%26pmt%3D1%26noa%3D1%26pg%3D4375194%26algv%3DRecentlyViewedItemsV2%26brand%3DFIR&_trksid=p4375194.c101770.m146925&_trkparms=parentrq%3Aecd6ccbc18b0ab8e6fdfdb8dfffe03d2%7Cpageci%3A9a303cd8-87a5-11ee-a14a-e2eac5278e76%7Ciid%3A1%7Cvlpname%3Avlp_homepage
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Post by shaunthe2nd on Nov 20, 2023 14:20:22 GMT 1
There is a kit you can buy for MX exhausts, it essentially blocks both ends, 1 end has a tyre valve, you heat the dent and pump in air, the dents pop out. Don,t know if it works on LC exhausts as they have a mesh inside the tuned length for noise reduction, may make dent harder to remove due to the thickness. Last time I looked they were around £50 Mark. Just a thought. If you have a link, that would be great. I've used high temp JB weld on small dents, also filled some with MIG without issue. Not tried this stuff, looks interesting for the lower temp areas. silverhook.co.uk/Big-boy-powder-coatable-metal-filler-250ml-high-temperaturePOA Sounds like it's the price of a house!
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Post by steve63 on Nov 21, 2023 12:49:40 GMT 1
Using air can be dangerous. Safer to use water. I bought a pump used for testing hearing systems. It uses water. I've not had a play with it yet.
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Post by Robbieben on Nov 21, 2023 14:35:06 GMT 1
Using air can be dangerous. Safer to use water. I bought a pump used for testing hearing systems. It uses water. I've not had a play with it yet. I've always used air personally, I cap the outlet and have a plug adapter with a valve in that goes at the inlet, inflate to 55 - 95 psi keeping an eye on everything as you add pressure, I measure the expansion on the pipe as I add pressure and then heat the area where the damage is in a circular motion, usually pop out with little bother, creases can take a bit of overcoming but generally even they can be coaxed out with heat and a planishing hammer. Water will work but youll lose the ability to heat as the water will act as a heat soak, the other side to water is that it distributes pressure evenly so there is risk of expansion on any part you pressurise. Air pressure distributes evenly but you create the weak area using heat, hopefully that is enough for the air pressure to pop out any dents, I've usually found this very succesful especially on my MX and Trail bikes where regular fettling was needed.
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Post by steve63 on Nov 21, 2023 20:42:19 GMT 1
Using air can be dangerous. Safer to use water. I bought a pump used for testing hearing systems. It uses water. I've not had a play with it yet. I've always used air personally, I cap the outlet and have a plug adapter with a valve in that goes at the inlet, inflate to 55 - 95 psi keeping an eye on everything as you add pressure, I measure the expansion on the pipe as I add pressure and then heat the area where the damage is in a circular motion, usually pop out with little bother, creases can take a bit of overcoming but generally even they can be coaxed out with heat and a planishing hammer. Water will work but youll lose the ability to heat as the water will act as a heat soak, the other side to water is that it distributes pressure evenly so there is risk of expansion on any part you pressurise. Air pressure distributes evenly but you create the weak area using heat, hopefully that is enough for the air pressure to pop out any dents, I've usually found this very succesful especially on my MX and Trail bikes where regular fettling was needed. I've not had a play with the pump yet. I did a bit of messing around with hydraulic pressure many years ago. Welding sheets together and pumping them up with water to form them. I don't know how much the water would affect the heating. Obviously it would affect it but depending on the heat source it could still go hot enough to work. I don't have any decent heat source at home other than a plumbing torch and that wouldn't be hot enough. Using water you could put a lot of pressure in there and still be perfectly safe. If it blows you just get wet. If you're using air then goggles AND a face mask are definitely recommended.
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Post by Robbieben on Nov 22, 2023 8:14:22 GMT 1
I've always used air personally, I cap the outlet and have a plug adapter with a valve in that goes at the inlet, inflate to 55 - 95 psi keeping an eye on everything as you add pressure, I measure the expansion on the pipe as I add pressure and then heat the area where the damage is in a circular motion, usually pop out with little bother, creases can take a bit of overcoming but generally even they can be coaxed out with heat and a planishing hammer. Water will work but youll lose the ability to heat as the water will act as a heat soak, the other side to water is that it distributes pressure evenly so there is risk of expansion on any part you pressurise. Air pressure distributes evenly but you create the weak area using heat, hopefully that is enough for the air pressure to pop out any dents, I've usually found this very succesful especially on my MX and Trail bikes where regular fettling was needed. I've not had a play with the pump yet. I did a bit of messing around with hydraulic pressure many years ago. Welding sheets together and pumping them up with water to form them. I don't know how much the water would affect the heating. Obviously it would affect it but depending on the heat source it could still go hot enough to work. I don't have any decent heat source at home other than a plumbing torch and that wouldn't be hot enough. Using water you could put a lot of pressure in there and still be perfectly safe. If it blows you just get wet. If you're using air then goggles AND a face mask are definitely recommended. Water under pressure can sever a finger or worse when under pressure. look how a waterjet works, they use water under high pressure as it cuts steel, air under high pressure wont cut anything and the main risk is if you happen to have your hand exactly over it and it bursts so can inject into the skin, anything more than 20 mm away and the air has lost enough pressure to only move something out of the way, water/liquid doesn't lose stream pressure anywhere near as quickly and fluid under pressure is still capable of breaking the skin at over a metre.
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Post by steve63 on Nov 22, 2023 14:08:26 GMT 1
I've not had a play with the pump yet. I did a bit of messing around with hydraulic pressure many years ago. Welding sheets together and pumping them up with water to form them. I don't know how much the water would affect the heating. Obviously it would affect it but depending on the heat source it could still go hot enough to work. I don't have any decent heat source at home other than a plumbing torch and that wouldn't be hot enough. Using water you could put a lot of pressure in there and still be perfectly safe. If it blows you just get wet. If you're using air then goggles AND a face mask are definitely recommended. Water under pressure can sever a finger or worse when under pressure. look how a waterjet works, they use water under high pressure as it cuts steel, air under high pressure wont cut anything and the main risk is if you happen to have your hand exactly over it and it bursts so can inject into the skin, anything more than 20 mm away and the air has lost enough pressure to only move something out of the way, water/liquid doesn't lose stream pressure anywhere near as quickly and fluid under pressure is still capable of breaking the skin at over a metre. A water jet as in water jet cutting uses a finely focused jet of water with fine particles in it under massive pressure, somewhere up to 400bar (around 6000psi in old money) to do the cutting. Without the particles, probably some kind of silica, there would be little or no cutting. If you get up towards 6000 psi and add silica inside your exhaust then just be aware of the danger . Watch any video of lorry tyres being inflated (with air) and the process going wrong to see how safe compressed air is at maybe 80psi/90psi. That's why they have safety cages to inflate them in (ok maybe not in India and China). We seem to have reached the point in this discussion where you are saying that repairing with pressurised air is safer than testing with water (water does not compress under pressure BTW). I know I am right, you think you are right. I think it's best to leave it there. I've done lots of things that aren't safe but usually I've known why and how they aren't safe and chose to ignore that knowledge. Generally it's not because I didn't know. Thankfully the HSE don't make unannounced visits to our garages yet so we are free to do what we want
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Post by Robbieben on Nov 22, 2023 14:38:08 GMT 1
Water under pressure can sever a finger or worse when under pressure. look how a waterjet works, they use water under high pressure as it cuts steel, air under high pressure wont cut anything and the main risk is if you happen to have your hand exactly over it and it bursts so can inject into the skin, anything more than 20 mm away and the air has lost enough pressure to only move something out of the way, water/liquid doesn't lose stream pressure anywhere near as quickly and fluid under pressure is still capable of breaking the skin at over a metre. A water jet as in water jet cutting uses a finely focused jet of water with fine particles in it under massive pressure, somewhere up to 400bar (around 6000psi in old money) to do the cutting. Without the particles, probably some kind of silica, there would be little or no cutting. If you get up towards 6000 psi and add silica inside your exhaust then just be aware of the danger . Watch any video of lorry tyres being inflated (with air) and the process going wrong to see how safe compressed air is at maybe 80psi/90psi. That's why they have safety cages to inflate them in (ok maybe not in India and China). We seem to have reached the point in this discussion where you are saying that repairing with pressurised air is safer than testing with water (water does not compress under pressure BTW). I know I am right, you think you are right. I think it's best to leave it there. I've done lots of things that aren't safe but usually I've known why and how they aren't safe and chose to ignore that knowledge. Generally it's not because I didn't know. Thankfully the HSE don't make unannounced visits to our garages yet so we are free to do what we want Yes, I appreciate the addition of micro silica in a waterjet, however water will cut steel up to 4mm under high pressure. Yes, I agree water doesn't itself compress but under pressure it can cause catastrophic failure where there is any weakness. We hydraulic test chemical & gas tanks using water. The safety controls we have to take are far greater than when we use air pressure first to do an initial test. I'm sure your method will work after all hydroforming is very common but at much higher pressures. I just don't see the need to add more risk to what is a simple effective procedure using air and a bit of heat.
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Post by steve63 on Nov 23, 2023 14:15:54 GMT 1
"Why is pneumatic test more dangerous than hydrotest?
Because pneumatic tests use a compressible gas, more energy is required to reach the required pressure. This energy is stored in the compressed gas and can be released explosively on failure. For this reason, pneumatic testing represents a significant hazard above and beyond hydrostatic testing. How much of a hazard?
An explosion of 200 ft. of 36 in. pipe containing 500 psi of pressure can create a blast wave nearly equivalent to 80 lb of TNT.
Pneumatic testing is much more dangerous than hydrostatic testing. Pneumatic testing requires higher levels of training, a pressure relief device is mandatory, and a higher safety rating of an enclosure such as TotalShield’s Shielding Rooms or Machine Enclosure is needed."
UK HSE Safety requirements for pressure testing
Guidance Note GS4 (Fourth edition): 15 "To reduce the stored energy in the assembly during a test, pressurise with water (or other fluid) rather than a gas wherever possible".
Not my words obviously.
We test refrigeration systems using somewhere around 450 psi of Nitrogen. We sometimes add Helium because the Helium Atoms are smaller and find smaller leaks, the leaks we are looking for are that small. We don't allow anyone in the room while testing. We only use gas because for obvious reasons we can't fill a refrigeration system with water as during use it has to be completely free of any moisture.
If water will cut 4mm thick steel without any type of cutting medium in it then I'd be happy to bet it won't do it at anything less than a pressure measured in thousands of pounds per square inch fed from a continuous pump. My compressor pressure relief valve goes off at 125psi.
I've cut wood with a jet wash just for a laugh and they can do maybe 2000psi. It might rupture an aluminium foil pie tray on a good day.
If you still think compressed gas is safer to use than water then fine.
My original statement was that water was safer to use than compressed air and I'm comfortable sticking with it. Like most people I'm reluctant to admit being wrong. Generally I will after seeing written evidence.
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Post by shaunthe2nd on Nov 23, 2023 17:51:06 GMT 1
My missus owes me a lot of paper work then!
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Post by Robbieben on Nov 23, 2023 18:29:03 GMT 1
"Why is pneumatic test more dangerous than hydrotest? Because pneumatic tests use a compressible gas, more energy is required to reach the required pressure. This energy is stored in the compressed gas and can be released explosively on failure. For this reason, pneumatic testing represents a significant hazard above and beyond hydrostatic testing. How much of a hazard? An explosion of 200 ft. of 36 in. pipe containing 500 psi of pressure can create a blast wave nearly equivalent to 80 lb of TNT. Pneumatic testing is much more dangerous than hydrostatic testing. Pneumatic testing requires higher levels of training, a pressure relief device is mandatory, and a higher safety rating of an enclosure such as TotalShield’s Shielding Rooms or Machine Enclosure is needed." UK HSE Safety requirements for pressure testing Guidance Note GS4 (Fourth edition): 15 "To reduce the stored energy in the assembly during a test, pressurise with water (or other fluid) rather than a gas wherever possible". Not my words obviously. We test refrigeration systems using somewhere around 450 psi of Nitrogen. We sometimes add Helium because the Helium Atoms are smaller and find smaller leaks, the leaks we are looking for are that small. We don't allow anyone in the room while testing. We only use gas because for obvious reasons we can't fill a refrigeration system with water as during use it has to be completely free of any moisture. If water will cut 4mm thick steel without any type of cutting medium in it then I'd be happy to bet it won't do it at anything less than a pressure measured in thousands of pounds per square inch fed from a continuous pump. My compressor pressure relief valve goes off at 125psi. I've cut wood with a jet wash just for a laugh and they can do maybe 2000psi. It might rupture an aluminium foil pie tray on a good day. If you still think compressed gas is safer to use than water then fine. My original statement was that water was safer to use than compressed air and I'm comfortable sticking with it. Like most people I'm reluctant to admit being wrong. Generally I will after seeing written evidence. I'm not disagreeing that gas under high pressure isn't dangerous, I know it is. However what I'm getting at is that an exhaust can easily be repaired using LOW pressures as low as 30 psi and a bit of heat up to 90 psi for stubborn bits if necessary. My air at say 50-60 psi rupturing a weak weld or similar won't do serious harm and is less risky than a pinhole with water under the same pressure. Water has the power at very low pressures 30 psi to break the skin injecting it into you, the same can't be said about air at such low pressures as the air/gas expands immidiately it breaks the pressure seal. Looking at the science you are correct but you are talking about HIGH pressures with the science you are quoting.
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Post by tony2stroke on Nov 23, 2023 18:59:01 GMT 1
Can I just say, You all know I love a good debate, but there is not one to be had here, the kit is not meant for using water, if you Google mx exhaust dent repair, you will see plenty of people using said kits, it relies on the heating of the dented area more than the air pressure, this becomes clear when watching the videos, which is why water won't work, around 30psi is enough.
They are great videos to watch, usually some half brained idiot, but even they can do it easily.
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Post by steve63 on Nov 24, 2023 19:32:01 GMT 1
"Why is pneumatic test more dangerous than hydrotest? Because pneumatic tests use a compressible gas, more energy is required to reach the required pressure. This energy is stored in the compressed gas and can be released explosively on failure. For this reason, pneumatic testing represents a significant hazard above and beyond hydrostatic testing. How much of a hazard? An explosion of 200 ft. of 36 in. pipe containing 500 psi of pressure can create a blast wave nearly equivalent to 80 lb of TNT. Pneumatic testing is much more dangerous than hydrostatic testing. Pneumatic testing requires higher levels of training, a pressure relief device is mandatory, and a higher safety rating of an enclosure such as TotalShield’s Shielding Rooms or Machine Enclosure is needed." UK HSE Safety requirements for pressure testing Guidance Note GS4 (Fourth edition): 15 "To reduce the stored energy in the assembly during a test, pressurise with water (or other fluid) rather than a gas wherever possible". Not my words obviously. We test refrigeration systems using somewhere around 450 psi of Nitrogen. We sometimes add Helium because the Helium Atoms are smaller and find smaller leaks, the leaks we are looking for are that small. We don't allow anyone in the room while testing. We only use gas because for obvious reasons we can't fill a refrigeration system with water as during use it has to be completely free of any moisture. If water will cut 4mm thick steel without any type of cutting medium in it then I'd be happy to bet it won't do it at anything less than a pressure measured in thousands of pounds per square inch fed from a continuous pump. My compressor pressure relief valve goes off at 125psi. I've cut wood with a jet wash just for a laugh and they can do maybe 2000psi. It might rupture an aluminium foil pie tray on a good day. If you still think compressed gas is safer to use than water then fine. My original statement was that water was safer to use than compressed air and I'm comfortable sticking with it. Like most people I'm reluctant to admit being wrong. Generally I will after seeing written evidence. I'm not disagreeing that gas under high pressure isn't dangerous, I know it is. However what I'm getting at is that an exhaust can easily be repaired using LOW pressures as low as 30 psi and a bit of heat up to 90 psi for stubborn bits if necessary. My air at say 50-60 psi rupturing a weak weld or similar won't do serious harm and is less risky than a pinhole with water under the same pressure. Water has the power at very low pressures 30 psi to break the skin injecting it into you, the same can't be said about air at such low pressures as the air/gas expands immidiately it breaks the pressure seal. Looking at the science you are correct but you are talking about HIGH pressures with the science you are quoting. No, It's not. End of.
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Post by steve63 on Nov 24, 2023 19:40:07 GMT 1
My missus owes me a lot of paper work then! I asked the insolvency agents, dealing with my case for incorrect payment of holiday pay after being made redundant, for written proof of what they claimed was the correct way of working out the payment. After asking them at least three times none was forthcoming so I exercised my right to an employment Tribunal and won my case. No written proof then it's just a load of hot air isn't it? Ker-ching, thank you! Bought a set of LC bodywork off Mark Cordwell with the result. Wives don't have to abide by that rule.
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Post by peter1962 on Nov 24, 2023 23:19:58 GMT 1
So What paint do you guys recomend
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Post by urbantangleweed on Nov 25, 2023 7:53:14 GMT 1
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Post by 4l04ever on Nov 25, 2023 10:25:21 GMT 1
LC OEM exhausts won't be easy to pneumatically push the dents out as they are very thick skinned, like some of the members on here :-)
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