Jump to content

 

Welcome to TheMalibuCrew!

As a guest, you are welcome to poke around and view the majority of the content that we have to offer, but in order to post, search, contact members, and get full use out of the website you will need to Register for an Account. It's free and it's easy, so don't hesitate to join the TheMalibuCrew Family today!

bscheper

Lost a tracking fin?

Recommended Posts

bscheper

I have a 2007 VTX.  Fortunately I didn't hit anything, but noticed bilge was running.  Hurried back to lift and found that the most rear tracking fin of the 2 was missing?  Looks like the bolts just pulled out of the fiberglass.  No major fiberglass damage.  Pulled a bolt out of the other fin and tried to screw in to see if it would bite but just not enough material.  Can I just fill holes with some sort of epoxy and epoxy base of fin and brace in place until all cures?  Or can I fill with epoxy, let dry and then drill a pilot hold and then just screw into that?  It is a six screw fin. (gorilla fin I think) The screws are 5/16 - 18 stainless.  Not really sure how a machine screw would have enough bite to hold the fin on.  Thoughts on how to approach this issue?  I don't really know where to start.  Read many threads about removing tank.  I pulled up the floor and see no way to get it out.  It goes 8" past rear and front structural support and there is not enough room to slide forward or back to get around supports.  Help!?

Share this post


Link to post
Share on other sites
bscheper

Well, I have completed more research and found that I have to remove the rear seat base to get the tank out.  Looks like it can wait for winter project.  I am hoping to just fill the 6 holes (gorilla fin) and run with 1 fin.  If it does ok I will wait until winter.  Any issue with this approach?  A couple questions.... What should I fill the holes with so I can drill it out easily in the spring?  3M 4200, 5200 or other? Basically 5/16" round holes. Everything I have read points to the fact that the fin is held on with 6 machine screws put directly into the fiberglass.  Is see no nut when viewing the front fin screws through the access port by the driver.  Is this correct?   I know I will get crucified for saying this but, I think I will just through bolt it on in winter.   (I know could cause more damage if I do hit something but I just don't want it to fall off again.)  Thoughts? 

 

Share this post


Link to post
Share on other sites
justgary

I think I would fill the holes with Marinetex.  Try to get it in the holes without trapping air so you have a firm bed for the new screws.

It might be worth horsing around with some fiber filler material mixed in the Marinetex before you fill with it.  Cotton balls would be a great choice.  It will give the filler a little tooth for the screws to grab. 

Once it sets you are good to drill and reinstall screws at your leisure. 

Share this post


Link to post
Share on other sites
JeffK

I would just get some cabosil and mix it with resin and hardener to fill the holes if that is what you are trying to do. 

Share this post


Link to post
Share on other sites
oldjeep

Resin soaked pieces of glass mat shoved up through the holes with a supper skinny needlenose and then pulled back down.  Then once that hardens more resin and chopped mat to fill the holes. 

Share this post


Link to post
Share on other sites
bscheper

Thanks for all the great ideas.  Now I think I am going to just buy 1/4" shorter (because not going through fin and I do not want them rubbing against gas tank inside) pan head screws, cover in 3M 4200 and screw in to get through the summer.  There is enough material to hold the screws until dry, just not sufficient to hold on a fin until I fix correctly in winter.  Thoughts?

Share this post


Link to post
Share on other sites
oldjeep

I sure wouldnt trust 4200 to hold lag screws. The real fix only takes a little longer than what you are contemplating 

Edited by oldjeep

Share this post


Link to post
Share on other sites
bscheper

Old jeep I see your real fix to plug the holes using resin and mat above. What is real fix to actually reattach this gorilla fin.  Can I just use your method above to fill hole now and then drill and attach fin in winter.  Trying not to fill holes with something that will cause me problems when attaching fin later and I am unsure how to do the real fix.  Remove gas tank or not since screws go in from bottom of boat.  Do I just drill into your method for fix?  How do I keep from puncturing gas tank? Do I need to tap prior to putting screws in?  I just have hard time believing that screwing into resin with mat will hold machine screws with fin?  Details on real fix to reattach fin would be appreciated.

Share this post


Link to post
Share on other sites
justgary

Several of us have already told you "real fix."  Before you commit your new fin to potential loss, try an experiment.  Find a scrap hardwood 2x6 (maybe from a large shipping pallet) that is somewhat larger than your fin.  Drill appropriate holes in the 2x6 that match the size and depth of the holes that you now have in your hull.  Try one of the methods mentioned above to fill the holes.  When the patch is complete, properly drill a pilot hole for the new lag screws and screw the fin to the board.  Now try to remove it through whatever evil means you can think of.  I bet you the wood tears out first.  If you have a scrap piece of fiberglass panel, use that instead.

The problem with your method of plug it with 4200 now and deal with it later is that you will never get the 4200 out to get a good bond unless you drill the holes even larger.  Fix it properly now, and forget putting it off with even more work to do.

As for the stuff and pull fiberglass method, the only thing I don't like is the inability to actually fill air voids later since you are working upside down.  Good technique with a putty knife will get everything in the hole in one shot.  Leave it proud if you want, then grind it flush after it sets.  Use fiberglass as a filler if you want (it really is the best choice), but I'm guessing you don't actually have any.  Maybe stop by your local fiberglass shop and ask if you can pick some up off the floor.  Better yet, offer the man $50 and a case of beer and he'll do the whole patch job for you on the spot.

Regards,

- Just Gary

P.S.  I just checked the MarineTex site for their answer to the stripped fastener problem.  Perhaps it's worth a look, because it has an interesting "twist" to it.

Share this post


Link to post
Share on other sites
oldjeep

Pretty much what just gary said. 

Fwiw bondo sells a fiberglass repair kit you can get in most auto stores or amazon.  Comes with some glass mat and resin.  Plenty for the job.  

https://www.amazon.com/3M-420-Fiberglass-Resin-Repair/dp/B000BO9NOO

 

I would be fixing/replacing both fins immediately rather than doing a prtial job and going back later. 

Edited by oldjeep

Share this post


Link to post
Share on other sites
Fabricator909

I have answered this question before in another thread, but get some epoxy resin, and milled fiber, which is fiber glass strands ground into a powder. Drill the holes out a size or two larger if the holes are in bad shape to get to good glass. Mix the epoxy resin and milled fiber into a peanut butter consistency, cut the tip off a syringe, fill it up, put the syringe into the hole. And squirt it in until it proud of the surface. Grind it down, take the tracking fin, mark your holes. Redrill and tap, most likely 5/16-18. 

Get the supplies from us composites if you dont know where to look.

Share this post


Link to post
Share on other sites
bscheper

Yes 5/16-18. Thank you!! That is exactly what I needed. I will fill and then drill and tap in a few weeks when I have fin and time.  Just didnt want to fill if I didnt know if it could be drilled and tapped when permanently putting on fin.  Will put 3m 4200 on base of fin and screws as well when attaching.

Share this post


Link to post
Share on other sites
JeffK
9 hours ago, Fabricator909 said:

I have answered this question before in another thread, but get some epoxy resin, and milled fiber, which is fiber glass strands ground into a powder. Drill the holes out a size or two larger if the holes are in bad shape to get to good glass. Mix the epoxy resin and milled fiber into a peanut butter consistency, cut the tip off a syringe, fill it up, put the syringe into the hole. And squirt it in until it proud of the surface. Grind it down, take the tracking fin, mark your holes. Redrill and tap, most likely 5/16-18. 

Get the supplies from us composites if you dont know where to look.

Are cabosil and milled fiber the same?  I have always thought they were, but wanted to confirm.  I had a fiberglass guy show me how to use it and it sounds very similar to what you just described.

Share this post


Link to post
Share on other sites
Fabricator909
1 hour ago, JeffK said:

Are cabosil and milled fiber the same?  I have always thought they were, but wanted to confirm.  I had a fiberglass guy show me how to use it and it sounds very similar to what you just described.

Cabosil is fumed silica, and is a trade name. They both have the same uses that I know of, I am sure one is better than the other for some applications and vice versa. I have read the Cabosil is harder to sand, which might make it better for tap and drill applications.

 

BTW to make installing the tracking fin easier after the holes are filled, get some double sided tape, and put the tracking fin in place, then use a self centering drill bit (wood working item) to drill the starter hole.

Share this post


Link to post
Share on other sites
Garry

I have a 2001 VLX (my tracking 2 fins are mid-ship).  A few years after purchasing it new,  I notice my bilge pump was also running frequently, and after pulling it (had to fill the INSIDE with water in order to source the leak) it was one of the tracking fin had come loose.   So rolled up my sleeve and thought - "no problem - How big of a job could it be, right"?

I pulled up the floor access plate, and could see the 1 fin bolthead,s but the gastank was blocking the the boltheads of the other fin.   Pulled up the rear seat access, unbolted the tank, and tried sliding it around to gain access, but nojoy.   after a few hours of trying everything I could think of, I called the marina, and they called the Malibu factory.   a few days later the solution came back as expensive news.  the solution was to remove the entire rear seat & metal support beam, in order to remove the gastank, in order gain access to the boltheads, in order to remove & reseal the tracking finx.   I pulled the boat into the Marina, and 1 week (and 10hrs of labor later), the fin were re-secured.    

now I treat the tracking fin with utmost respect, as I never want to go thru that $experience$ again....   

Share this post


Link to post
Share on other sites
footndale

So slight tangent, why does Malibu through bolt V-drive fins and not DD fins?

Share this post


Link to post
Share on other sites
justgary
8 hours ago, footndale said:

So slight tangent, why does Malibu through bolt V-drive fins and not DD fins?

Only thing I can figure is expected use of the boat.  DD is more likely to be used on smooth, protected water, V-Drive is more of a runabout....

Share this post


Link to post
Share on other sites
bscheper

My 2007 vtx v drive is not through bolted unless the bolt is buried inside the hull.  I have not 100% figured that out for reconnecting on problem above.  I can see through access port the bolts for the front fin and there is no bolt on the 5/16-18 screws holding the fin.

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


×
×
  • Create New...