opinions needed on weld re-repair

[SPYDERLK]

Cracks end in stressed but uncracked metal. You drill beyond the end of the crack so that the crack barely intersects the hole. When welding - If crack goes all the way thru - grind about 1/2 thru, clamp flat and weld. Grind from other side until you reach the weld - then clamp flat and weld. Do not leave weld proud to surface. This will leave it stiffer than the surrounding metal and it may crack next to the weld. Consider use of a needle scaler for cleaning and strain relief during cooling via the shot peening effect.
Larry

 

[thingy]

Most times you can't SEE the end of a crack,,,why drill at some point,when you can use a technique that is used every year in every power plant and refineory across the world,to find extent of crack???,,,when they find a small crack in a weld or haz in a 48 inch sch 80 2 1/4 chrome or more pipe,that has steam in it or a crack in a stainless pipe that has stuff in it that can kill you,they don't drill a hole in it,,they do p.t. or other ndt methods to check extent of crack,,and,,more importantly,make sure they get crack out.Drilling a hole is what they did in the old days cause they didn't know of a better way. thingy forgot to add here,,thats after the steams out and the stuff that can kill you is out of pipe,,its not cause they have to do it that way,its the way industry does things,,they don't replace anything they don't have to,,they don't drill holes when they find a damned crack,they check the extent of crack,,repair or replace,that oughta be good enough for a tractor part to,you would think??,,,thingy

 

[Casey1]

Sounds good to me. After all that it should be the strongest part on the tractor. LOL

 

[thingy]

One more thought,,you got to find the end of the crack or it may grow,you seem to know that,,but what guarantee do you have that by drilling a hole like you say will get to the end of that crack?? cracks are sometime open so you can see ,sometimes not,in any case they got an end,,,by using an ndt method as simple old long standing as p.t.,you can see that crack,,,old school,,thats what they did back in the 30's to see how far a cast iron part cracked,,,[even though p.t. was available than],,,mag partical is another way you can check for cracks,,,but,p.t.,,,if used correctly will show any crack open to surface,and you don't need to stress relieve a part like this,,,and if you did,,peening would not be it,,,needle scaler? yeah most people have one of them handy,,thingy

 

[Soundguy]

Crack runs from an edge ending at a bolt hole..

Soundguy

Read KennethBrown post again. If the ends of the crack don't end in the bolt holes, or if they start on the other side of the bolt holes, the part is going to continue to fail if you don't stop the running of the crack. You might add enough extra metal to stop it, but the best way is to drill the end of the hole as was suggested.
Only reason I re-mentioned was due to you not mentioning it.
David from jax
Since if is a hard part to find, while you have it off, consider drawing a template of it and hanging in the barn so in case the worse happens, you won't have to resurrect the piece, just grab the template and remake it. Kind of one of those insurance plans. If you have it, you will never need it. If you don't have it, you'll need it soon.
David from jax

 

[Egon]

they don't replace anything they don't have to

The repairs are usually based on the minimum downtime.

Soundguy has a predrilled hole. Now its to the grinding and keeping things in the proper place.

 

[SPYDERLK]

thingy, peening is good to relieve the tensile stress introduced by the cooling weld. I use a needle scaler between passes to clean and destress, and after final pass,and then again after grinding the weld to blend smoothly with the surface. As you know, this leaves the surface with a compressive stress and inhibits crack formation.
Larry

 

[thingy]

Yeah,there is nothing wrong with peening it,,won't hurt nothing,,its just not necassary in this case,,besides,most people don't have a needle descaler.
egon,,thats true,to a point,,,sometimes they find cracks and don't repair or replace cause they think it will last a while longer,,just saying that when they do decide to get a crack out,,they don't look at it and drill a hole at what they can see to be visually the end of crack,,they generally use p.t. to chase cracks,if they decide to repair,,sometimes they replace. When I say they,,well,I guess I should say me,cause on alot of the jobs I am on,,its my job to do this,at chemical plants,power plants,refinorys,,,most times the cracked item is replaced,,but sometimes company wants to try and fix it up,,depending of course on what it is,,,thingy

 

[KennethBrown]

Hey thingy- Lets just do it your **** way ok? It was simple advice from a simple person. Yes, your way is a BETTER method.

PS- I did not see that it ended in the bolt hole, where did it say it started?

 

[thingy]

Beats me,,all I heard was crack. Drilling a hole is a way of trying to get out end of crack,I agree with that in principle,thats the way they used to do a lot of castings,and it generally works,if the hole is big enough,,liberty bell, I think is an example,don't think they ring that anymores because it cracked again?
But,they got stuff now that makes it much easier to find the ends of cracks,and its cheap,and easy to use,thats all I am saying. Plus,if the crack don't go all the way through a piece,you don't need to drill a hole all the way through it,and plus,plus,,if you drill a hole in something,you probably want to fill the hole back up,and if not done right, that could lead to more problems than you had to begin with,plus,plus,plus,you gotta drill a hole through 3/8 to 1/2 steel,when you don't need to.
If you or anyone else out there have never heard of dye penatrant,and you ever think you might need to try and weld up a crack,than you have just learned something,you should stop at your welding supply place and see if they could get you some,,could really come in usefull.
Just trying to help out here with something I know alota bout,[no expert in anything],but ,this kinda stuff is what I've been doing for about 25 years now. Thanks all the same,thingy