Moomba Boomerang Rebuild

[95_moomba]

The Gray on the side walls is probably some sort of primer used to seal the fiberglass the gray in the middle not sure what it is but since this area of the boat sees the most water its probably similar to a bed liner material that 100% water tight. I have this same boat and thought about doing what you are doing but mines not in that bad of shape i have one hole under the drivers seat and one near the back left thought about fixing them from the outside but i want to make sure its right so probably going to fix them from the inside. The fuel tank has 4 mounts two in the front and one on each side take a phillips head driver to remove the screws + the 3 hoses attached. Ive owned my for 2 yrs now and only had to replace a transmission and soon a starter maybe but they are fun $8k boats when running and one of the coolest looking boats on the lakes and rivers.

[markedenfield]

The hardest part of this transformation was trying to figure out the three-axis curves of the stringers. After searching every forum I could find, I found all of them to be absent of a sure-fire way to do it other than trial and error. So, within about four hours and a new planer, I fit two stringers. In addition, I've struggled with the ribs that do not extend to the sides of the boat. They fall shy of about four to five inches of making it all the way. I suppose they are strictly used for floor support. Another trial will be setting the engine beds back into the proper angle. The old ones (what was left of them) were measured by placing a 6' level across the gunwales and measuring down to the top of them. They are actually installed at an angle (the beds) in order to assist with meeting the transmission/prop shaft angle.
Could you take a measurement and tell me how far the shaft comes out of the seal area. Just let me know how you measured it as that was the only one I didn't take before removing the engine. Here is a photo of the motor.

[95_moomba]

sure ill try and get that for you this afternoon

[95_moomba]

it is 12 and 1/8 inch from the end of the transmission plate that the shaft bolts to, to the edge of the rubber closest to the bottom of the boat. I can try to take a picture if this does not make since to you.

[markedenfield]

Thanks. I found a markable difference in the color of the prop shaft where it had been spinning for years.

How are your engine beds tied in? Are they laminated to the stingers? Do they extend down and touch the hull?
What type of bolts attach the engine mounts to the beds? Lag bolts?

Thanks,
Mark

[95_moomba]

Yes lag bolts hold the motor in place. as far as the eng beds it looks like they are glassed in or to the floor. Did you have to cut the top layer of the floor out to see the bottom of the hull on the left and right sides. I have to take the top layer out to fix a few holes on each side before summer gets here but they look to be glassed in?

[tunnels]

Originally Posted by 95_moomba

Yes lag bolts hold the motor in place. as far as the eng beds it looks like they are glassed in or to the floor. Did you have to cut the top layer of the floor out to see the bottom of the hull on the left and right sides. I have to take the top layer out to fix a few holes on each side before summer gets here but they look to be glassed in?

Lag bolts last about as long as it takes to put them in the boat rought water and a boat hitting a sand bar or what ever and you motor could shift and move !!!
Steel plates then drill and tap a thread is a better option , Just make sure you put a load of glass over the tip and make sure the plates will stay for ever .

[markedenfield]

Yes, the floor is glassed to the sides of the boat which made it seem incredibly difficult to remove. It also has that grey material which has to come off as well so the new glass will adhere. That was harder than the flooring itself.

I finished grinding the last bit just this morning. Never again will I take a full project like this on. It is whipping my butt and I haven't even started to put the new stuff in. I've cut the stringers, bulkheads and two of the ribs but that's it. I used 3/4 ply for the stingers. I even bonded (with PL) two 3/4 together so it will be quite strong. I just need to make sure I spread the hard spots out on each side of the stringers by at least 12 inches.

I'm replacing the floor with 1/2" ply but will glass both sides and the edges before putting them in.

I was going to use epoxy resin (West System) until I figured out how much it would cost then I switched to Poly. It is about $28/gal for poly and the cheapest West Epoxy I could find was $80/Gal. This thing isn't going to be making a trip around Mars so I figured Poly resin would be fine. I'll add wax to the final coat so I can sand it smooth.

Putting the engine back in has me a bit worried. I took all the measurements I could before removing everything but there is little room for error. The engine mounts adjust a wee bit but...

[markedenfield]

Originally Posted by tunnels

Lag bolts last about as long as it takes to put them in the boat rought water and a boat hitting a sand bar or what ever and you motor could shift and move !!!
Steel plates then drill and tap a thread is a better option , Just make sure you put a load of glass over the tip and make sure the plates will stay for ever .

When you say "steel plates" do you mean angle or flat? How thick would they have to be and how do you adhere the plates to the engine beds? Seems like at some point something has to be lag bolted down unless we are relying on something like 1708 over the steel. You mentioned to glass over the tip, was that the tips of the tapped in bolts?

Help me understand this process better as I am getting close to a test fit of the motor.

[95_moomba]

Originally Posted by tunnels

Lag bolts last about as long as it takes to put them in the boat rought water and a boat hitting a sand bar or what ever and you motor could shift and move !!!
Steel plates then drill and tap a thread is a better option , Just make sure you put a load of glass over the tip and make sure the plates will stay for ever .

They have been holding it in place since 95. I agree your idea is probably better for holding it in place but these are lake and river boats not taking on 4ft swells in the ocean.

[95_moomba]

I cut access holes in my floor and thought i would let you know the floor braces are not glassed to the bottom they are glued or caulked in and the floor is screwed to it.

[markedenfield]

Sorry it took a bit to get back to you.

I have test fit the engine and it looks good and with a few adjustments it should be fine. Finished cutting the rest of the stringers, bulkheads and the few ribs I'm putting in. Will begin glassing them tomorrow with 1.5 oz cloth. I'll let them sit for a day and then install them in the boat with PB under them, CSM and 1708 biaxial up each side. Since I have the 1.5 oz on the cap of them already, I probably won't do them again. Then the floor. Using 1/2 exterior ply and I'll cover that too with 1.5 oz cloth and then install. I really don't want to use screws anywhere so I may PL them in. Don't know yet.

I am still struggling with using lag bolts again to secure the engine mounts but I cannot think of anything else to use. I could bore through the beds and stingers and bolt them with stainless but I doubt I could soak the interior of the holes enough with resin to keep the water from destroying them. Any ideas?

Does yours have the bilge air inlets on the deck with a tunnel-like structure built from them into the engine room? LOL

[95_moomba]

yea I dont see any other way other than lag bolts for the eng... yes i do have the air inlets but they dont run to the eng bay they are just there I have blower in the back that pulls the fumes out of the bay but thats about it.

[markedenfield]

I've just about got the stringers glassed in. It's a long process if you follow (I think) Dr. Yachts mindset with the 1.5 CSM x 2 and then the 1708. Drinks lots of resin too.

I included two pics. First one should be of a rib, the second one is the deck just to the left of the drivers seat...the area where I asked about the vents coming in from the top deck. Notice the holes (upper right of second photo) cut in the flooring to accept the hoses? What a mess that area was. Trying to figure a way to keep water out of the are (forever) is going to be tough if I run the 3" vents from the bow into the bildge. Takes up most of the bulkhead (front of the bildge) surface area.

Do you plan on removing the cap to rebuild? If not, what a joy it is crawling underneath to clean and then reapply.

[tunnels]

Dr. Yachts mindset with the 1.5 CSM x 2 and then the 1708. Drinks lots of resin

Wont do that again will you ?? why would anyone in there right state of mind want to lay 1 x 1.5 of csm ?? thats silly absolutly insane !! If you used epoxy why are you using csm in the first place ?? wow !! Did you use any peel ply over the top ?? :