scarab31

I am at about the same point as you are ramos45 in replacing the transom on my 89 Scarab Excel 31, so much fun. All three of my stringers had moisture at each of the engine mount through bolts only, otherwise they came out in pretty big pieces. My transom looked like garden mulch from the very bottom to about 4 inches above the bottom of the outdrives. In the process of making a cardboard template and then trial fitting. Question of the day: how do you get an 8 foot wide piece of plywood back in the boat? Seems awfully damn tight for space not having done the actual fit test yet. All this started when all I wanted to do was upgrade from the stock to newer 496 exhaust manifolds and risers.

ramos45

iTrader: (1)

I hear ya man. I knew I had a leak so I anticipated some repairs but this is flying out of control now. I am learning a lot though. I'm making my template out of a 4'x8'x1/2" sheet of insulation. I haven't cut it yet but I did take some rough measurements of my transom. I will cut a rough template from those measurements and then fine tune it in the boat. The template and wood will have to be maneuvered in through the top and then pushed flat against the transom. When it's time to actually bond the new transom we are going to have to wet the backside of the new wood from its backside, does that make sense? Then we will have to push it up against the back of boat. I'm ordering my materials this week and will try to cut my wood this week also. I'm ready to finish this. Good luck Scarab31.

Katanna

iTrader: (1)

Looking good-and itchy. Make sure you you grind or trim the areas where you pulled the smaller stringers out, flat with the floor. You dont want any ridge sticking up that will make it harder to lay in the glass creating a void. Technically a scarf joint should not be notched, it weakens the wood at the corners and could cause it to split. I would cut your ends off at an angle from top to bottom. Scarfs are generally at least two times as long as they are high. You have the benefit of the knee near your engine mount to strengthen it. Speaking of mounts, pull them out! How many times have you bashed into those edges? lol You will want to reseal the holes anyways. Cepes is great but I wouldnt waste the money. As long as you take out enough bulkhead to get back to clean wood, just get the edges nice and wet with resin and you will be fine. It will be better than original.

ramos45

iTrader: (1)

I just looked up scarf joints and I see what you mean. I really don't have enough room to have such a long angle cut so I think leave as is and "sister" the joint for reinforcement.

I'm going treat the bulkhead the same as the transom in that a layer of mat will be goinn first to laminiate the new wood to existing glass. I'm thinging of extending that layer of mat out past the joint onto the flat surfaces remaining for added strength. What would be better for this, mat or 1708?

Katanna

iTrader: (1)

The corner of the notch in your stringer cut makes it weak and creates an area for a potential split. I would sister it on the outboard side from the knee to the transom and it will be stronger than new and not noticeable. Even if it is only 45 degress I would make it one straight angle. The 1708 is good for the bulkhead and the tansom.

scarab31

Thanks. I've been reading the different threads from other people who have also replaced their transom's knowing it was just a matter of time before I was replacing mine. I need to replace the forward bulkhead on my boat too and need to post a picture. Looks like yours extends fully from side to side whereas mine is only about the width of the fuel tank only. I've always wondered what the hull differences are between the Scarab III and Excel models actually are???

ramos45

iTrader: (1)

Actually, my bulkhead isn't one piece. It's 3 pieces with the stringers from forward cockpit breaking it up. I'm going to replace it with one solid piece and glass it so that the stringer wood doesn't touch the bulkhead wood

scarab31

All old wood removed including transom, stringers and bulkhead at the rear of the fuel tank. Cleaned any grease or dirt with acetone and sanded all the edges and areas where I will be tabbing in the transom and stringers today. Marine grade douglas fir (4 sheets) tomorrow, need to order the fiberglass material.

ramos45

iTrader: (1)

I got knocked off my time table this past weekend so hopefully can catch up this coming weekend. I did manage to score some wood, 2 sheets of marine for the transom and two sheets of 7ply for the stringers. All materials should be in this week.

Post some pics of your progress.

ramos45

iTrader: (1)

I never thought I would get to this point. I'm finally done with the major grinding. Tomorrow I'll take care of some corners that I have to get into with a dremel then clean up and start glassing. Here are some pics. Sorry for the angles, it was the end of the day and I was tired.

[ATTACH=CONFIG]518237[/ATTACH][ATTACH=CONFIG]518238[/ATTACH][ATTACH=CONFIG]518239[/ATTACH]