89OT repair / fix 'er up

[Meridian_Mike]

Hey guys....
I have been absent from the bench for a while but a new project has lit a fire under me.
I got this 89OT really cheap because the main blade is BADLY tipped. I don't want to try to put a new tip on the existing main blade.

SO.......
I thought maybe I might try to find a new main blade. That has turned out to be a BIG CHORE.

That being said..... (and I hope this won't upset any purists) .....
I might just put an 8OT blade in for the main blade. I do have an 8OT parts knife with a nice main blade. My first impression is that the kick and profile are sufficient to replace the 89OT main blade.

Y'all got any thoughts?
I am not trying to fool anyone into thinking this will be a "factory mistake" knife. I just love the serrated secondary blade of the 89OT.
Heck.... I have some good ole jigged bone... so I might just put on some new covers too.
Here is the patient sitting in my ER.

More later....

[dlr110]

Good to hear from Mike and good luck with the project...

[doglegg]

Does an 880 have the same main blade as the 89 OT?

[glennbad]

Good to see you around, MIke! That's probably a swinden construction. As long as you're aware of that, as you'll have to make it a through-bolster pinning now.

I may have an 8OT blade somewhere, if you need one...

[Meridian_Mike]

Good to see you around, MIke! That's probably a swinden construction. As long as you're aware of that, as you'll have to make it a through-bolster pinning now.

I may have an 8OT blade somewhere, if you need one...

Thanks Glenn!

I have a few 8OT blades I can choose from in my parts stash. The over all profile of the 8OT main blade that has the same tang stamp as this 89OT I have, seems to be the same blade blank. I will take some pics to show this when I get the 2 blades side by side and on top of each other. I could see Schrade having one big stack of this size clip point blade blanks at this time in production for all their offerings. The only difference being the "number" of the pattern stamped under the Schrade name. (USA 89OT.... USA 8OT).....

I will probably pin the blades in since I like that method for (in my opinion) as being stronger than swinden construction.

[Meridian_Mike]

Does an 880 have the same main blade as the 89 OT?

That is definitely a possibility.....

The main focus of the blade I will use will be the kick. I do intend to do a mock-up using the liner and spring to see if the blade I choose actually fits well.
I HOPE.... LOL.... I can get enough pics during the project to post here so others can benefit.

[Meridian_Mike]

OK.....
Yep.... Swinden construction..... which means you can't remove the main blade without cutting the Swinden pin.....

Here is the 89 OT blade compared to the 8OT blade......

(Sorry for the out of focus pic)..... Here is the 89OT blade compared to the 8OT blade in a basic mock-up with the old Swinden pin in place.

As things look..... I should be able to use the 8OT blade with a few minor adjustments for final fit.
NOW..... let me see if I can dig up some nice cover material for this project. My mind is running free in a field of jigged bone!....LOL

Onward!!

[Meridian_Mike]

OK..... a quick mock-up shows the kick on the 8OT blade is a little shorter that the 89OT.

89OT in place....

Now.... the 8OT in place.....

The picture of the 8OT blade in place also reveals another possible problem. The blade tip on the 8OT blade might interfere with the spring (a good bit actually).
I know that the slack in the remaining Swinden pin might make this look worse than it really is BUT.... I can see a definite difference between the fit at the kick on the 89OT original blade and the 8OT blade that I want to sub in.
More work and fitting in the offing.....

Onward!

[Bill DeShivs]

If you're careful, you could extend the backspring with a couple of good whacks with a hammer, and widen it where the kick touches it.

[Reverand]

Or, solder a thin piece of steel or brass shim to the back spring where the kick touches it. I suppose that you could glue it, but I would worry about the long-term durability of any glue.
I have soldered several back springs, with no discernable difference to the spring tension. Hopefully it anneals the spring enough to keep it from ever breaking, but does not seem to lessen the snap.

[Meridian_Mike]

Thanks for the advice guys! All very good ideas.

Here was my solution......
I have seen evidence of this done on older knives. I have seen where the kick was "stretched" and extended a bit by peening it. This sort of "mushrooms" the edge and extends it some. A few examples of this on older knives is very evident. It looked like some kicks were smashed in by a punch and leaving the shape of the end of the punch on the kick. I found it interesting that no attempt was made to hide or dress up this method of extending the kick.

SO..... I measured from the spine of the blade straight down to the kick. Then with some careful peening on both sides of the kick, I stretched the measurement out few thousandths. Then I carefully filed the edge flat for a good contact surface. The result was an extra 5 thousanths from the spine to the tip of the kick. After I got this new measurement established, I did a full mock up to check the clearance.
Here is the result, good clearances everywhere......

If you look at the kick you can see the area where I peened. It did change the thickness of the kick slightly since there is now a slight taper at the very edge where the kick meets the spring..... As you all know, it only takes a little change at the kick to get a lot of change at the tip of the blade. That was my intention by stretching out the metal just a little. Now I can sand the outer faces of the kick and get the shine back to the same as the rest of the tang.

Today I will clean the blades and other parts. AND, I think I am going to add some new covers. I found a piece of saw cut bone that gives the same finished look as the original plastic covers.

[doglegg]

I'm enjoying the process Mike.

[Reverand]

Look at Meridian Mike, getting this DONE!

[Meridian_Mike]

Thanks guys!!
I did get a few things done yesterday afternoon. I cleaned up the blades and liners.
Then, I drilled my bolsters with the jig I made that was inspired by Muskratman. I love using this thing. It holds the bolsters square so you can drill the Swinden "keyhole" at the spot where the pin should be when I convert to pin construction.

Here is a shot of the blades. Getting the milling marks off the blades turned out to be a little more of a challenge than I expected. I hand sanded the blades all the way up to 2000 grit.

Next will be thinning out the bone to get a nice thin cover that will be the same thickness as the covers I removed.
More in a few days......

[Meridian_Mike]

Here is a bit of an update....

I didn't get the covers I put on last weekend to fit as well as I wanted so I figured I would go back to the drawing board.

First, I scribed the shape of the cover onto a slab and used the band saw to cut out the rough shape.....

This time... I used a micrometer to check the thickness of the cover material.

I took the blank that I had cut to the basic shape of the original cover and scribed a line on the edge so I would have a sanding guide.....

Then, I took the cover blank and kept sanding until I got a blank that was the same thickness as the original cover.

After I got my thickness RIGHT THIS TIME....LOL.... I fitted the new cover to the liner, then glued it in place.

Now, after the glue dries, I can drill the cover pins and peen the covers onto the liners.

NOTE....
To all who are using this thread to learn MY procedure, it is MY opinion..... there is NO GLUE (that I know of) that can hold a cover on permanently. You REALLY NEED to use pins just like the original construction to keep the covers on (unless you want to put the knife on a shelf and just look at it).

More to come.

[orvet]

Good work Mike!
Nice tutorial also.

[TripleF]

I don't do any repair of this type but find this very cool!!
Can't wait to see finished product!!

[Meridian_Mike]

Well.... about time huh?....LOL
I actually got some time this afternoon to get out to my shop. Here is the final installment of this repair / mod.
I got the pins in and cut off. Then comes the filing and peening of the pins.
It is very important to file the tops of the pins flat before peening....

I used 2 slackers before I started peening, one on either side of the center liner.......

Then I peened the bolster pins.....

Here she is with all the pins peened.....

Then came the final finishing and sanding.
Here is the final product.......

No more broken main blade. I guess this is an 8OT with that little bit extra!!!!

I hope this helps someone that wants to learn a little about folding knife repair. I ain't sayin' this is the right way or the only way..... This is just the way I do it. I hope y'all enjoyed the process.

Mike

[Meridian_Mike]

My son just saw this post and said to call this knife an 89.8 OT....

[doglegg]

Thanks for sharing Mike. I like your sons humor.

[treefarmer]

Just read through this thread and enjoyed following the progress of your knife! It looks so much better with the sawn bone handles than the normal Delrin handles but the real beauty here is the detail of how you overcame the problems of making a similar but different blade fit the frame.
The extent of my knife work is very limited. I'm pleased when I can reshape a tipped blade. You fellers that are knife mechanics are truly craftsmen!
Treefarmer

[Reverand]

That looks better than a new one!

[Meridian_Mike]

Thanks everyone!
I posted this so maybe some who are thinking of trying pocket knife repair would have a little something to go by.
It is very rewarding to take a "discard" knife and make it usable again.
Y'all have a great day!

[glennbad]

I'm really liking this, great work!

[Meridian_Mike]

Thanks Glenn!