Hello all. I am hoping I can get some repair advice from others that have had this problem. My current situation is that I have two ss gudgeon screws that were broken off inside the transom on my starboard hull during a race in Myrtle Beach (a couple of years ago I am ashamed to say). I don’t think I ever hit anything, must have just been some sort of weird stress on the rudders. I also have to ss gudgeon screws with broken heads on my port side rudder. They are all the upper part of the gudgeon. I have gone through numerous drill bits and hours working to get these ss screws out with little success. I’ve learned to take my time and drill slow, but we are talking hours on one screw here. I have also messed up and gone through the aluminum backing plate in some of the hole locations accidentally. I’ve made some progress, but I need to start thinking about how I am going to make this a lasting repair so I can get back on the water. My boat is pieced together with 86 hulls. She was pretty fast and light last I remember. At this point I’m not really looking to get back into racing just yet, I just want to be able to have some fun with her and the wife on the water. I have the one piece gudgeons and plan on using them.
So, my questions are:
1. Do I just continue to try and drill out the ss screws (I’ve been using cobalt bits), fill with resin and filler (btw I have no fiberglass experience), and then re-tap with a larger size screw?
I really worry about doing this correctly. I think it would be hard to get them all back into the aluminum. Drilling these screws out has not gone well. I’ll get into the screw, but it isn’t perfectly center and the screw eventually sheers off making it even harder to drill out.
2. Do I do the above step and try to glass in helicoils? (seems expensive, compared to other options)

3. Do I cut inspection ports into the stern of each hull to thru-bolt the new gudgeons?

While more drastic, this seems like an ultimately easier and more sure-thing repair. It would also allow me to make sure the transom is sealed.

4. Some option that I do not know about????
I’m open to anything at this point. What would be the fastest, cheapest, and most effective way to do this repair? I’ve got to get back sailing.
I will try and post pics of the transoms in a few. Thanks in advance.

We had some discussion about the same subject about a month ago on this forum. Also with a H16 as I remember.

I would choose definitly for option nr. 3

Fastest (and maybe best in the long run) might be to pay to have it done. Definitely not the cheapest, but shouldn't be too bad. It's not like you have major glass work to be done (such as a t-bone hole).

Mike

+1 for option 3. Much easier to repair in the future and it is nice to have access to that area of the hulls through an inspection port

Drilling a screw out is not an easy task and it is usually not cheap.

*Grind the broken screw flat

*Mark the center with a punch

*Use a center drill to start the hole

*Drill a pilot hole all the way through the screw. The pilot hole should be no larger than 1/2 the dia of the screw

*Drill the screw out in at least 2 steps

To drill out a 1/4 inch screw you start by drilling a 3/32-1/8 hole all the way through the screw without breaking the bit. This takes a steady hand, lot of sharp bits, cutting fluid, constant pressure on the drill and the right drill speed. Never ever try to drill with a dull bit. The normal SS screws work harden. Just spinning a dull bit, will harden the SS until steel bits will not cut(cobalt bits are cobalt steel by the way). You need a solid carbide bit to drill through it.

There are kits that promise to make this easy and there much more expensive kits and tools that center the hole and keep the drill aligned and square.

There are alternatives

Use a Dremel tool with a 1/4 in cylinder grinding stones and just grind the screw away. This produces a lot of heat, don't set the boat on fire. This will take several aluminum oxide stones. They make a carbide bit that has smooth sides just to do this(expensive). This takes about an hour and you have a ragged hole to fill.

My newest favorite is the diamond one piece hole saw. There is no center drill. You fit the hole saw over the screw and just cut a hole around the screw. Then I used a bigger hole saw to make a plug out of G10 and drilled it for a helicoil. The saw has a limited depth of cut. You may have to do this in stages.

If there is a Hobie dealer in your area that does repairs you might get an estimate and then compare that to what it will cost for you to remove the screws. If it were my boat I would estimate $30 per side to remove the screws and put in helicoils

Thanks for the input everyone. I think I will install ports and thru-bolt the gudgeons. It seems like my best option. I don't know of anyone local that I could get to do the repairs and cost is a huge factor. I think I am up for the port installation.

Carlbohannon, I think I know the bit you are talking about. I purchased one of those to drill around the ss screw. It was nice to be able to see the screw and know where the aluminum backing plate was. Do you think that bit will go all the way through the aluminum? This is what I have been using more or less, they are pretty expensive though at 15 bucks or so a pop

http://www.toolbarn.com/hitachi-728020.html?gclid=COmks5jl87kCFfFj7Aod9X8Afg

If that will go through the aluminum, then I am just going to drill around the screws and bore a hole, fill with resin and filler, re-drill, thru-bolt, and seal it all up and GO SAILING!

Do you worry about the helicoils failing because they are not set in the aluminum backing plate?

My next question would be...what are the best ports to use. Should I order from Hobie or somewhere like Annapolis Performance Sailing?

Always buy from Hobie, we need to keep the dealers and company alive. APS does is support regattas at times, but they are largely in the dinghy market.

Mike

The diamond bits I use are made by Lenox and are rated for metal. Yours are for stone and tile and probably have finer teeth. Both will cut aluminum. Yours will have issues with clogging the "teeth". I would use a water based cutting fluid to minimize aluminum sticking to the cutting surface.

If you are going to the trouble of installing a port, I would just thru-bolt. Helicoils, inserts, etc are used so you don't have to have access to the back side.

BAM!

I would do #3. However I would cut out the existing backing plates and replace them. I haven't installed the one piece gudgeon on a boat yet. Does it use the existing holes or are they all in new locations? If it's all new locations then you can drill and tap. If you can't get the bolts out now you won't have any better luck from behind through a port. To cut them out a dremel tool works but I prefer using one of the sonic tools like the Rockwell sonicrafter. Works great and easy to control with less dust. You can buy 1/2" plate stock by the foot from McMaster Carr. I've also simply knocked them out by using a punch from the outside and just drive the plate out. Generally that plate is only covered buy a single layer of light cloth. To prevent this from happening again coat the screws with Tefgel.

you can just buff that out!

kidding aside - is that a goner or repairable?

Repairable, but being that I haven't heard from the fibreglass guy for three weeks I'm thinking I should've just bought a new hull. It's either going to be a horrendous bill, or he just hasn't had time to work on it. I'm hoping its the latter.

Unless you've got a pile of bits and pieces left almost anything is repairable. It's just making sure you don't cross that line of replacement vs. repair costs.

gotcha

That's a pretty easy repair. It's in a nice flat section of hull with no non-skid to deal with. You can lay up flat patches and flat pieces parts to fill and repair. If it wasn't right in front of the front beam, I wouldn't hesitate to seal it with packing tape and keep sailing (it is probably a structural problem with where it appears to be, however).

I finally bought a set of reverse drill sets. As you lube and drill, the broken bolt will heat and finally screw out.

Rick, in hindsight that is exactly what I should of done. I had heard of left-handed bits, but no one around here carried them and I was too impatient to order them.

Know what you mean. I don't know how many time I wished I had them.., finally found them at Northern Tool and got them. Have not needed them since.., haha

Flag down a Snap-On or Mac Tool truck. They all have them and I'll bet they are better quality than at Northern. A little pricier...but they are worth gold when you need them.