gimbal replacement disaster

[krisnowicki]

I tried the plug kit. Well it worked well but when I went to tap the hole... man this did not work out. I am using a 1" pipe tap and it would not tap right. So now I have two 1" holes in the shield. what should I use to cover. I was thinking of having it welded. Or getting two stainless steel plates and tapping small holes and screwing them down. OR... metal tape then jb weld over the top... of course sanding and preping first... what do you think? I will post pics tommorrow

 

[JustJason]

Re: gimbal replacement disaster

hmmmm.... maybe some thin aluminum... the stuff you can get at depot that's like 1/8th thick. It cuts fairly easy on a scroll saw. Cut to size then maybe smack some 5200 of choice on the back then rivet the corners in place.....
then sand prime paint it......

 

[Don S]

Re: gimbal replacement disaster

Welcome to the real world.

A few years ago I used to get mad when people wanted to do that, then all the back slappers came on and said how great it was, and how I was just trying to make the job look even harder.
Obviously when those chosen few did it, it worked out. I stopped saying it was a bad idea, again, welcome to the real world of boat repair.

 

[krisnowicki]

Re: gimbal replacement disaster

my p[lan was similar to that... I was going to add a coat of jb weld after wards to make sure it was sstrong...

 

[Don S]

Re: gimbal replacement disaster

That's exactly what I would want on my boat. Some thin aluminum held in place with some adhesive that may or may not hold.

 

[krisnowicki]

Re: gimbal replacement disaster

well as it was a part of the manual I thought if i did the job according to the manual it would work... oh well... terrible ... I could try a 1 1/4 pipe tap man this is frustrating. if this repair is not part of the real world the should remove it from the book...

 

[JustJason]

Re: gimbal replacement disaster

glue + rivets.......

 

[achris]

Re: gimbal replacement disaster

I'm with Don on this one... Do the job right, or hand it to someone who can....

Just remember that the small ali plate and the JB weld is all that is between you and the seabed!

Chris......

 

[Don S]

Re: gimbal replacement disaster

glue + rivets.......

Rivets? ? ? ? ? ? Pop riviets have holes thru them. Real rivets you have to get a bucking bar on the backside.
Why not just slather a bunch of sillycone over the area and hope for the best.

 

[JustJason]

Re: gimbal replacement disaster

It was a thought

 

[krisnowicki]

Re: gimbal replacement disaster

I'm with Don on this one... Do the job right, or hand it to someone who can....

Just remember that the small ali plate and the JB weld is all that is between you and the seabed!

Chris......

for the record I followed the manual to the T. I cut out the template gathered all the tools. My point is, if even the most capable mechanic (don s)finds this method abhorrent or that it may be performed by the "chosen few" then it should be removed from the manual.

 

[chiefalen]

Re: gimbal replacement disaster

Can you post a pic so we can see where you are?

Without the pic, can you tap it and screw a plug in it?

Or it's not thick enough?

 

[krisnowicki]

Re: gimbal replacement disaster

I will post a pic tongiht... I am not at home now. I cannot tap it... I have tried two 1" npt taps.... IT just grinds the metal away not leaving theads... Fortunetly, I did one side and relized the botch job to come and then stopped so the other side just has the small punch hole in it from where I used the template to set the job up.

I am so frustrated.

 

[ziggy]

Re: gimbal replacement disaster

to start with, i've not done this repair, so i'm a greenhorn. took me a few days to even decide what yer talking about. i assume yer replaceing the gimble ring. but what i'm wondering is why the tapping didn't go well? i think this is a possible cause.

So now I have two 1" holes in the shield.

if i read right. it's a 1 1/8" hole ya wanted, tapped w/ a 1" npt..... if ya really drilled the hole to 1''. perhaps ya can figure away to get it up to 1 1/8" so ya can use the proper plugs????? i think i'd be concerned about what achris and dons are saying. glued on plates between you and blurb blurb... sounds a scary to me...

IT just grinds the metal away not leaving theads.

to me, that's a sign of not having the proper size hole to tap into too...

 

[krisnowicki]

Re: gimbal replacement disaster

first I don't have 2 1" holes right now. I have 1, 1 1/8 inch hole on the port side. I was saying would have two if i finshed the job. I used all the right tools. when I used the tap which I have done before it does not leave threads just shaves the metal.

 

[ziggy]

Re: gimbal replacement disaster

when I used the tap which I have done before it does not leave threads just shaves the metal.

only other possible help i can give is that are ya useing pretty good end pressure on the tap? the aluminum and cast aluminum i've taped is very soft. the new screw threads being cut don't help pull the tap into the hole very well. like when yer tapping steel. very easy to just pull the new threads out of the aluminum hole. hence i've used pretty good end pressure on the tap + go very slow with a lot of in and out of the tap clearing out any debrit that gathers on the tap.... good luck...

 

[achris]

Re: gimbal replacement disaster

As Ziggy says, lots of end pressure on the tap. I've done this job quite a few times, never with any major problems. I also use only grease, not cutting fluid, it helps pick up the cutting chips and start the threading process.

Chris..........

 

[krisnowicki]

Re: gimbal replacement disaster

I will try to tap it again on tuesday. thanks for your help guys sorry to bother every one...

 

[45Auto]

Re: gimbal replacement disaster

Pipe taps have a LOT of taper to them (that's why they're called "tapered threads" .....). The first part of the tap will usually be sized to just grind the metal away as you say before it actually starts cutting threads. You want a good bit of end pressure on the tap as others above have stated.

Normal drill size for a 1" pipe thread is 1 1/8 then you taper ream the drilled hole before starting to tap. So in your case the tap has to grind the hole out to 1 1/8 before it can think about starting. If you're not using a reamer the drill size you normally use is 1 9/64. I would post the table from the book for you if I had a scanner handy. Info from Machinery Handbook, 27th edition.

I think Merc has you start with the small hole (1") to MAKE SURE you get the threads into the thin aluminum, since you'll only get 1 or 2 threads at the most. If your hole isn't to big for the plug already then you're probably still OK. Have the plug handy while you're tapping and check it every 1/4 turn or so of the tap to see how far it goes in the hole. A little bit of tapping makes a HUGE difference on how far the plug will seat into the hole. Can't tell you the number of times I've seen a tapered thread cut too deep.

If the hole IS already oversized and messed up I wouldn't even think about trying to patch it with epoxy, tape, etc. Just asking for a sunk boat. A new transom shield, welding or a machined plug would be the only ways I would think about trying to repair it. PM me if you do have problems with the hole being oversized.

 

[krisnowicki]

Re: gimbal replacement disaster

If i can't get it plugged... I will probably weld r have it welded...