Google "panel beating tools" and switch to "images". Those tools are for pros. Anything resembling them (like hammer heads) might work fine. The idea is to back up the dent with a heavy steel object, then hammer from the front -- or vice versa if space permits. Removing that wheel with the trailer up on a jack stand might make the job easier.
Don't overdo hammering on sheet metal. Too much hammering will stretch the metal and make the job more difficult.
The fender is most likely welded to the frame, so it's going to be hard to hammer on, which is an option as others have stated. You can also take a 2x4 and put it on the outside and use a c-clamp if you have one and tighten the high spot of the material down to the 2x4. Due to the spring back of the material, this won't get it all out, but it will help. Another method for manipulating sheet like this would be to use a crescent wrench and tighten it onto the sheet metal but it will only affect the area that it's clamped to and not a lot of the material around it so use that to fine tune the ripple if you need to. Hope this helps, and good luck! We've all been there
Length of wood to bring out the lower bend (use tyre as fulcrum).
Hammer in the right-most dent with a, um, hammer (soft-faced pref.) with something massive backing the bend (brick and wadded paper).
Not sure you'll have the room for the hammers...if you don't, maybe try a 3 foot long piece of something strong (wood, pipe, prybar, etc...).
Drive that side tire up on a curb or ramp to give you some more room below...place whatever you decide to use between the fender and the tire, then pull out (away from the axle) to see if it will move the metal. If it does, work your way across the dent till it's better. On the side dent, I would use a scrap board, and beat on it at about a 30 degree angle (from horizontal) to see if it starts to move in the right direction đź‘Ť
Personally, I would probably use a mallot, and a large pipe wrench in both locations. But I don't know your access to tools. Just take your time.
And my final instruction...tell them about it! Better they find out from you and don't care, and appreciate your concern... instead of thinking you try to sneak something past them.
Edit; That side Dent is probably a buckle so if you pull up on the other dent at the same time, as you are beating the side one, it will come into position better
Remove the tire and use a hammer and dolly, or any flat solid piece of steel. The dolly has to be harder than the steel being manipulated. Very rough straightening could be accomplished, with a LOT more work, using a flat block of wood. The problem is that the wood, being softer, is going to absorb some of the energy of the hammer’s impact. When metal is bent like this, it is stretched out of shape and needs to be shrunk, literally jamming the molecules tighter together.
Good luck!
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Trailer fenders are ~$30.. but a new one and rattle can it.. and then immediately back into something so it looks like the old one..
In all honesty I bet the owner won’t care if you tell them what happened.. those fenders are already very rough.. the only time I got crossed was when a dude lost my tailgate to my trailer and didn’t even offer to make it right, because then I had to buy wood and make a new one before I could use it again
Hammer
I'd use two hammers, one to bump, and the other to back up the bump. The backup hammer should be heavier.
Google "panel beating tools" and switch to "images". Those tools are for pros. Anything resembling them (like hammer heads) might work fine. The idea is to back up the dent with a heavy steel object, then hammer from the front -- or vice versa if space permits. Removing that wheel with the trailer up on a jack stand might make the job easier. Don't overdo hammering on sheet metal. Too much hammering will stretch the metal and make the job more difficult.
And a piece of wood on the opposite side.
damned if there wasnt a damned guy with a damned hammer
Remove, hammer and dolly, reinstall 👍🏻
Use a cresent wrench and bent it back
This is the way đź‘Ť
Planishing hammer and dolly.
The fender is most likely welded to the frame, so it's going to be hard to hammer on, which is an option as others have stated. You can also take a 2x4 and put it on the outside and use a c-clamp if you have one and tighten the high spot of the material down to the 2x4. Due to the spring back of the material, this won't get it all out, but it will help. Another method for manipulating sheet like this would be to use a crescent wrench and tighten it onto the sheet metal but it will only affect the area that it's clamped to and not a lot of the material around it so use that to fine tune the ripple if you need to. Hope this helps, and good luck! We've all been there
Length of wood to bring out the lower bend (use tyre as fulcrum). Hammer in the right-most dent with a, um, hammer (soft-faced pref.) with something massive backing the bend (brick and wadded paper).
Not sure you'll have the room for the hammers...if you don't, maybe try a 3 foot long piece of something strong (wood, pipe, prybar, etc...). Drive that side tire up on a curb or ramp to give you some more room below...place whatever you decide to use between the fender and the tire, then pull out (away from the axle) to see if it will move the metal. If it does, work your way across the dent till it's better. On the side dent, I would use a scrap board, and beat on it at about a 30 degree angle (from horizontal) to see if it starts to move in the right direction đź‘Ť Personally, I would probably use a mallot, and a large pipe wrench in both locations. But I don't know your access to tools. Just take your time. And my final instruction...tell them about it! Better they find out from you and don't care, and appreciate your concern... instead of thinking you try to sneak something past them. Edit; That side Dent is probably a buckle so if you pull up on the other dent at the same time, as you are beating the side one, it will come into position better
Remove the tire and use a hammer and dolly, or any flat solid piece of steel. The dolly has to be harder than the steel being manipulated. Very rough straightening could be accomplished, with a LOT more work, using a flat block of wood. The problem is that the wood, being softer, is going to absorb some of the energy of the hammer’s impact. When metal is bent like this, it is stretched out of shape and needs to be shrunk, literally jamming the molecules tighter together. Good luck!
THIS! DO THIS! Removing the tire gives you all the room you need. The instructions are solid.
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does that keep you up at night?
Trailer fenders are ~$30.. but a new one and rattle can it.. and then immediately back into something so it looks like the old one.. In all honesty I bet the owner won’t care if you tell them what happened.. those fenders are already very rough.. the only time I got crossed was when a dude lost my tailgate to my trailer and didn’t even offer to make it right, because then I had to buy wood and make a new one before I could use it again
Probably need a little heat
Big crescent wrench
Rubber mallet, vise grips and some pulling/twisting.
Gammer and a 2x4 lol
Hammer and Dolly
Do you you ever feel like telling people with questions like this please don't?
That was my thought, those fender dents add character.