Pages

Sunday, May 8, 2016

Alberg 30 Refit: Alberg 30 Mast Beam Reinforcement Coming Together

 Spring time is finally here. The weather has been consistently about 50 degrees at night, 60-65 during the day, just perfect for epoxy work. I've also had a week off from running the ferry, giving me a great opportunity to get some much needed boat work completed. This beam project is starting to come together. If you were confused about what I was trying to accomplish maybe this series of pictures will help. 
I have been using some higher level mathematics to construct this new reinforcement and I don't want to bore anyone with the details so I'll just say.....I hope it works. A lot of time and backyard engineering has gone into this project. 

 This is the mast beam all stripped down and waiting for reinforcement.
(This was a photo from last post)

Here I've added some WestSystem 406 thickened epoxy to help bring the surface of the original beam level. What you cannot see is the several layers of 1708 biaxial fiberglass cloth I added to increase the strength of the support. As the original epoxy from applying the cloth began to gel, I added the thickened epoxy and then let it set overnight.

After sanding the beam smooth it was time to drill the holes through the original beam and new G10 reinforcement plate. For all those who wonder what is in the original beam of the "liner" Albergs, there is in fact aluminum in there, although I believe it's just two separate 1/4" plates. When drilling into the aluminum on the first hole, as expected I hit the aluminum but then rather quickly I was through it. As the drill bit continued I hit another piece of aluminum. I was able to drill through that rather quickly as well and before I knew it the drill bit was through the other side. The hole on the starboard side drilled identically, so for all those that are curious my boat has what appear to be two separate pieces of 1/4" aluminum within the beam.

The new G10 reinforcement all epoxied in....now on to the new beam that will reinforce the aft part of the mast step. I asked the first mate to coat all the new stainless hardware with a balm so the epoxy wouldn't stick to it. I intend to leave them in when it's all finished but for now I want them removable so I could sand everything down without them getting in the way.

Out came the trusty orbital, armed with 36 grit disc. Sanding commenced on all 12 pieces that make up the new 1" X 3" beam

Getting each piece sanded was not too bad. After this step all pieces were wiped thoroughly with acetone.

Here is the new beam in place. I use thickened epoxy to laminate the new beam. My plan all along was to laminate it in its final resting place. I drilled 3 small 1/4" holes and passed bolts through to the coach roof top. These bolts were fastened tight by the first mate out on deck. They hold the center of the beam firmly in place. Next step was to apply pressure to the outer edges of the beam. I accomplished that with 2 scissor jacks and some 1"x 1" pieces of lumber. I then jacked some pressure into the new beam.
WHAT A MESS!! All the excess epoxy started oozing everywhere. Luckily I was able to control it. I left this setup and allowed it to harden for two days just to be certain. West Systems says complete curing is 1-4 days.

Next I removed all the hardware and jacks. I broke out the orbital and went to town. Everything cleaned up nicely. I am still in the building process so it doesn't have to look perfect just yet.

Next I cut a new lower piece, you can see it sandwiched in between the piece that will eventually make the archway and the newly-placed reinforcement. I made the piece wide enough to sit under both sides of the beam reinforcement. This will also provide a solid surface for the archway to butt up against. 

Then it was time to start making templates for the knees (gussets) that will support the newly laminated beam.

Straight on shot of my reinforcement project

I now have templates for the port and starboard knee. I also did a center knee that is not pictured.

Starboard knee

This template was for the forward mast beam reinforcement plate. Once I had this cut and drilled, it was time to start cleaning everything up with the orbital, give everything an acetone bath and epoxy it into place.

I now have everything epoxied in place and will leave it to cure for a few days.

 G10 reinforcement plate viewed from the v-berth. I gave the original beam forward side the same treatment as the aft side. I ground away all the loose and poorly laid up material. I filled it with fiberglass cloth and thickened epoxy. Only difference is I did it all in one day. I am not familiar enough with the West Systems epoxy and how long I have to work with it before it starts to cure that with proper planning and everything laid out I can get much more accomplished rather than having to go through several curing cycles. Speeds things up quite a bit.

I accomplished a ton of stuff this weekend. I will take those templates I made for the knees and fabricate them from 3/4" G10. Once the knees are fabricated I will make the archway. 
We'll see how it goes!