Limits of bent bar

[livemusic]

Just curious, does anyone know the limits of how much a guide bar can be bent and be repaired? I saw a bar repair tool that claimed any bar could be fixed. LOL, I wonder if they really mean that. Say a bar is bent severely, like a 20 degree angle, could that be fixed or is only for very minor bends. If it were bent to that 20 degree angle, seems even if it was put back, it would be weakened. But what do I know, that's why I ask!

I also bought a saw and the seller sent me a bar that he said was bent and that I could get it fixed but I can't even see anything wrong. I don't know if this question matters regarding laminated versus solid. I guess most people use laminated, such as a Stihl Rollomatic E instead of the ES.

 

[Woody912]

Just curious, does anyone know the limits of how much a guide bar can be bent and be repaired? I saw a bar repair tool that claimed any bar could be fixed. LOL, I wonder if they really mean that. Say a bar is bent severely, like a 20 degree angle, could that be fixed or is only for very minor bends. If it were bent to that 20 degree angle, seems even if it was put back, it would be weakened. But what do I know, that's why I ask!

I also bought a saw and the seller sent me a bar that he said was bent and that I could get it fixed but I can't even see anything wrong. I don't know if this question matters regarding laminated versus solid. I guess most people use laminated, such as a Stihl Rollomatic E instead of the ES.

I bent one 30 degrees plus, straightened myself with a bore into a stump and later on a pane of glass. Have used it a lot but it does have a tight spot in it when I bury it. Mostly use if for limbing

 

[livemusic]

I bent one 30 degrees plus, straightened myself with a bore into a stump and later on a pane of glass. Have used it a lot but it does have a tight spot in it when I bury it. Mostly use if for limbing

How the heck did you use a pane of glass, lol?

 

[Woody912]

How the heck did you use a pane of glass, lol?

Used glass to check for straightness, marked the high spot and put it in a vise and bent it again. Repeat as needed. Bore hole in the stump was best trick, I had a tree to finish!

 

[Cj genever]

How the heck did you use a pane of glass, lol?

Floated glass is perfectly flat. Place it on a flat surface do it doesn't bend (ie cast iron saw table) and use it to gauge your progress

 

[Big_Wood]

i was taught by old loggers. pull bar off and support the bent part on a stump. hit with your axe in the center (staying away from the rails). the support on the stump will prevent it from bending to far the other way.

 

[Chainsaw Jim]

If you're strong enough to make it straight without cracking or pinching the rails then you're good to go.

 

[Macman125]

I would imagine one wouldn't want to heat a bar to bend it straight as it would mess with the temper?

 

[Rx7man]

I'm looking at a 390 that a yarder flopped over onto.. nice 36" husky bar on it bent real good... I figure I can straighten it again..

I think any bar that has been bent that much is going to suffer a little from it... it'll be a little softer, but most of the time if you jammed it badly enough to rebend the old bar you'd bend a new one too.

think if you put a stack of feeler gauges (I have some extra long ones) in the bar groove before unbending it, it would help prevent it from pinching.

 

[Big_Wood]

I would imagine one wouldn't want to heat a bar to bend it straight as it would mess with the temper?

i'd never heat one up. like you say, it would lose it's temper. it is also not needed at all. the stump and axe technique is tried and true.

 

[Rx7man]

My friend says just a ball peen hammer and a steel plate, tap it in the high spots. The 390 I'm looking at has a new stihl RS chain on it.. that alone is worth $60 here

 

[rwoods]

OP, yes, bars can be bent severely and straightened. There are probably some that can't be salvaged. I bent a 33" bar two Saturdays ago - 45 degrees +/-. Maybe I was too timid but I was unable to completely straighten it using a bored slot in the stump and 5# axe technique. If my life had depended upon it I would have tried harder and longer. Below is where I got it in the field. A machine shop finished straightening it. It still has a small bend that only a machinist would notice near the tip; he gave up on making it perfect for fear it would break where the tip mounts. Ron

 

[Woody912]

My friend says just a ball peen hammer and a steel plate, tap it in the high spots. The 390 I'm looking at has a new stihl RS chain on it.. that alone is worth $60 here

I don't think a tap is going to do it. I used a vise because I believe you are going to have to bend it past center because of the spring. Sort of like straightening an aluminum arrow. Might have to be redone periodically as well. Have heard one of the local old time loggers made a straightener using steel rollers, sort of like a tension leveler used on sheet steel but have never got to see it in action, if Charlie made it I'll bet it worked. One additional thought, bar may be bent in to 2 planes( twisted) so using the glass or other dead flat surface shows where you need to go in both ways