Hey Bear Collectors!

[oldbohntr]

I’ve got an A mag riser with a stripped latch screw mounting hole.   The screw looks ok, so I’m assuming it must be the female threads in the riser.  Has anyone had good luck with anything like JB Weld or similar to fill, drill, and tap for these holes?  The screw is so short is doesn’t fit my gage very well….is that a 4-40 thread?

[Hobow]

Tom, I had a similar problem with the strike plate of my B riser.  I wanted a permanent metal repair so I pre-drilled an aluminum machine screw, drilled and tapped the riser, screwed the epoxy covered screw in tight and cut it off flush once dry.

I then counter bored and tapped it and it's been perfect!

Some general pics are in the attached thread although I did completely photograph the whole process intending to post a work-along...

Brad

 http://tradgang.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=14;t=006032

[Hobow]

TTT - the loctite thread maker kit worked pretty good on an old Holley carb.   Not sure how well it would work with such short thread engagement.  

I found an older post by Inrut -

Latches with the little bears to the riser. 4-40
Latches without bears. 6-32
Limb locator pin 8-36 NOT 8-32 as some think!
Sideplate screws 2-56

[oldbohntr]

Brad,

Yeah, not much engagement, and a carburator may not face the stresses that this would.

I saw your post on the aluminum screw repair method.  I’m afraid of trying that here because the holes are so close to the radius on the edge.  If a bigger screw fails to work, then I’ve got a mess!  At least, the stripped hole is the one opposite the locator pin.  I always thought it was a design flaw that the locator pin hole conflicted with the latch screw hole and interrupted full thread contact.   Had a bunch of these risers, though, and never found that hole stripped!  
Interestingly, the threads bite when I leave off the latch…but only on the last couple of threads.  Not enough that I would feel confident without more thread contact.  
I ran a 6-32 tap in gently with my fingers and it wouldn’t bite in either hole because of the taper on the tap.  There is just no safety factor designed in, as it is on the other end of the limb seat.  I’ve never done it but have been told you can string one of these with the latches open –seems likely to be true.  This end though, could pull out when the string comes down and I think that would be disastrous!   I’m afraid loc-tite threadmaker or JB Weld might not have enough contact to bond either.  The best idea I can come up with is to align/level it the best I can in my drill press vise and drill/tap all the way through with an 8-32 thread. Then to install oval head 8-32 screws and paint them black(not likely I can find blued ones). I would do both sides for symmetry and because it should strengthen the overall attachment.  The alignment pin hole would be weakened, but I would guess there’s not much stress on it as far as pulling out.   What do you think?  
It’s a beautiful riser, refinished in black krackel, and the only Bear T/D riser I had intended to keep.  Sold at least 15 that were original finishes over the years and this one just stayed with me.   It’s not good to anyone if I can’t fix this though.  Because I found a loose screw on another one some years ago, I tested all I had and this one was stripped….I was careful and confident I hadn’t caused  it, but who knows?

[Gun]

Tom
I had to untstring mine and take a closer look. I think you would be OK to redrill and tap. But before that maybe look into a bottom tap in the size you need. There are 3 different types of taps in any size for starting-finishing a thread. (And many more for NC etc) In a bottoming tap the thread goes all the way to the end. Mind you there is still a bit of an angle to help it start in a hole.

I can tell on one of mine its just about thru the riser. If that doesn't work you can get by with going next size bigger with out hurting the strength I would think.

Your drill should follow existing hole but it may help to insert drill in hole first, then clamp in chuck to line up and clamp in vise.

I don't think a fill would work as it would probably chip loose as soon as you drilled again. LB weld is some pretty amazing stuff tho.
Good Luck

[oldbohntr]

Thanks, Gun.  But, now I'm leery to rely on any of the threads that are there.  Thinking it through further, if I'm going to drill on through and tap it, I may as well do it first for a longer #6 screw on both sides.  If that seems to hold, I can stop there.   Hopefully, I can find both #6 and #8 oval head screws.  

I always thought the mag riser was the most bomb proof of all Bear t/ds.  The more I look at this thing, the more I realize there is not a lot of safety factor designed into these short tapered- screw threads engaging the softer material in the handle.

[Hobow]

Hi Tom,

I agree that the JB probably isn't the best course of action.  I'm kind of leaning towards a slightly longer screw since your's will bite without the latch in place.

Judging by the small size and the fact that the riser can be shot without the latch locked down, I'm inclined to think that the screw is mainly to locate the latch and under very little, if any stress.  

I assume that it's probably been shot many times while being stripped out without any downside.

Drilling would be my last resort. I would look for a black oxide steel screw rather than trying to "color" a stainless screw as the stainless will corrode in the riser and seize over time due to the chemical reaction between the two metals not to mention that hardware store stainless is softer than the steel fastener.  

I'll check my old compound when I get back home and see if the screws are longer.

Brad

[oldbohntr]

Brad,
No, take another look at a mag riser and see if you don't think I'm right.  You can(presumably) shoot a bear t/d with the latches undone because the limb butts are seated in the pockets and the locator screw and string tension prevents the limb from unseating.  (look at all the bows, like the old Herters t/d, where the limbs just sit in a pocket.)  But, these screws are on the other side of the latch, in the back and the forward travel of the limb could possibly "lever" these screws right out of the holes! Take the screws out of the latch of a mag riser, if you have one, and insert a limb in the latch/riser.  Push the limb forward slightly and you will see what I mean. It simply folds forward.

Maybe I'm fretting over nothing, but I don't think so.  Maybe it would only happen if the string breaks, and maybe it really doesn't take much thread contact to hold it all together.  I agree, it must have been shot at least some time with the stripped thread-I bought it used/refinished at least 15 years ago, so I don't have any idea.  I did shoot it some - and it felt just like any other Bear T/D bow.

yeah, slightly longer screws are likely to work. But, the holes are darn near through the to the limb pocket now, and it seems the easiest is to drill them through, tap them, back the screws out, cut them off, and reassemble. Then I can have good thread contact clear to the bottom of the hole, with a screw that is not tapered.  Should make a stronger assembly, don't you think?

Heck, it seems to me it would be stronger than the original design.

[Kelly]

Hi Guys;

Well this talk about loose screws and them supoosed to be black and then there is talk about the chrome or stainless ones and got me to looking at my mag risers. Have 9 of them and only two with black screws-rest all chrome/stainless. So wha tis up here with mine-are those 7 with the chrome screws/limb pins all be after market replaced?

Speaking directly to your problem Tom I too have one loose screw/limb pin on an A mag and it is stainless-it is possible that it was replaced as the handle has been refinished by a previous owner so I'll need to fix it as I want to use this handle myself.

Incidently, quite a few of my mag handles are the flocked ones and all but one of them has chrome/stainless limb screws/pins.

[oldbohntr]

Kelly,
Obviously, I just don't know.  Had 15-20 mag risers over the years and most were hunting models so most had black screws. Whichever screw coating, it seems to me

[Hobow]

Tom,

I see what you're talking about now.  It makes sense that the limbs could place a load on the latch assembly during the recoil from a shot and definitely from a broken string.

I do have an A and a B riser and after looking closer I agree that drilling all the way through and grinding the screws to length is your best bet, I forgot how thin that area is.  I meant to say that drilling oversize would be my last resort.

I checked my Bear compound that uses the same riser and the screws are identical to the T/D riser, same size, length and thread so no luck there on the longer screws.

Kelly/Tom,

My warning about the stainless fasteners was concerning those that are found at the local hardware stores which are a very low grade, soft steel meant for appearance only.  My experience with seizing is from automotive and offshore boat use in aluminum and magnesium and didn't want the same to happen with your bow.

[Kelly]

FYI, all of my Mag risers are either A or B.