Nitro 170 transom rebuild and questions???

[RStewart]

You're doing a good job so far. I'm fixing to start my own restore on a bass boat. Tight bond lll WILL NOT fail. You will destroy the wood trying to get them apart. The guys on here give advice based on their experience & the experience of others. All the guidance you need is on this forum. I'm going to subscribe to your build & follow along.

 

[Woodonglass]

Uhmm, TB III is some of the best wood glue ever made. As RStewart stated once the glue cures you would have to destroy the plywood to separate it. I'd say the majority of the restorations in the past year on this forum have use TB III to glue the Transom and Stringers together for their boat restorations. It's your boat and you're free to use any glue you want. Epoxy does have the best adhesive and water resistance characteristics of all the adhesives use in boat building. It's also the most expensive. If you don't mind the cost then by all means use it. You still wouldn't need to use fabric between the two layers of plywood.

 

[boat86fish]

Ok, good. I think I'll go with the titebond, save the epoxy for the main job. I like the help so far. this project is a job I will only want to do once!

 

[IUPapabear]

Looking good. Going to follow along as well.

 

[boat86fish]

Got the transom laminated today. I decided to use titebond III to glue it together. I sanded the mating surfaces with 60 grit then applied a generous amount of glue then clamped it firm.

I have a question on waterproofing. My thought is to wrap the whole transom in 3oz E-glass cloth and let it cure before I install it. Will this be a bad idea for bonding to the back, if I sanded the back and PB it in, will that be ok. I want the best bond on the back. What your thoughts?

 

[Woodonglass]

Since you're using epoxy no fabric is needed. Coat the transom with epoxy and when it cures, Mix up some cabosil and if you want throw in some fibers from some shredded glass fabric,with your epoxy to the consistency of creamy peanut butter and spread on a 1/4" layer on the back side and clamp it home. Don't squeeze to hard You don't want to squeeze all the glue out.

 

[boat86fish]

Uhhggg... I think I may have a redo.
I found this void on the bottom of the transom. It looks like it goes in a quarter of and inch. There is a couple other spots along the bottom, but not as bad. I made the mistake of applying the glue to one side then clamping them together. Now I'm worried that I have air pockets trapped inside. Not good... :facepalm:

 

[boat86fish]

Well..... after looking it over some more I think I will scrap this one and do another. No sense installing it if I'm not confident it will hold. I'll order another sheet of plywood and build another. Don't like this set back...oh well..

 

[Woodonglass]

If I may offer a bit of advice. Your mistake was two fold. Not gluing both panels and not doing adequate clamping. As I suggested previously, it would be Much better to glue the panels and then Pre drill one side and use deck screws to screw them together. Using a 4" spacing on the screws would ensure that the panels had good clamping compression all across the area. This may be concerning to you putting all these screw hole in the transom but I assure you it's NOT a problem, and it's done all the time. Once the transom is cured and dry you can, if you wish, remove the screws and then apply resin to fill the holes or let the PB fill em when you install it. Removing the Screws and filling with resin IS NOT REQUIRED but you Can do so if you want to. It's perfectly acceptable to leave them in the transom and install it Screw site facing forward and cover with the 1708 and CSM. Place the Non Screw side up against the hull.

 

[rickryder]

When I need to bond 2 pieces of ply like that I roll on the glue both sides then screw it together like WOG said. I like using something like these..

http://www.thewoodwhisperer.com/videos/handy-glue-rollers/

 

[boat86fish]

The plywood came in today so I went at the transom again. I decided to epoxy it together instead of titebond glue. I sanded, cleaned then coated both sides till it was completely soaked then let it tack and added a layer of fiberglass between the halves. I found that epoxy seems to work much better as it is thicker than the wood glue, no gaps or bubbles. This time I got a good laminate.

Now I need to get some way to keep the back area warm at least 65 degrees when I go to install the transom and lay the fiberglass. This cold weather is not fun. I'm not looking forward to the long curing times.

 

[rickryder]

Heat lamps facing the transom from the outside should warm it enough for it to kick...

 

[boat86fish]

I got to work on the transom some more tonight, getting it fitted. I think I should have it fitted good now.

I do have one issue though. There is about a half inch gap along the bottom. I did have to grind a lot there when I was grinding the hull. So... dumb question....will I be ok filling the area with peanut butter, that will be strong enough...right? My plan is to tab the whole transom front and back with 6 inch then an 8 inch wide strips.
I hope to attach it this weekend if I don't come down with the flu by then.

 

[RStewart]

Looks good.I would say you will be OK filling the gap with PB, but I'm not an expert so hopefully one will be by shortly to chime in. Fill your body with lots of vitamins & minerals & that will help keep you from getting sick.

 

[rickryder]

When you coat the back of the transom with PB and clamp it in place it will ooze out all around it so your gaps will fill.....if you need to you can add and fillet (cove) it with a large metal spoon dipped in acetone.

Also looking at your clamps you may want to use 2x6's on their flat so it spreads a better load across the transom...if you just use the clamps the pressure will be mostly at the 3/4" point of contact. Putting wood on the inside and out would be best.

 

[Woodonglass]

RR has given you some SAGE advice about your clamping. It's extremely important to get good clamping pressure across the entire area of the transom those c clamps are Less than optimum for doing the job correctly. You should use the 2x4 for sure. How do you plan to get pressure along the bottom portion of the transom???

A 1/2" gap is no problem for the PB to fill.

 

[boat86fish]

My plan is to drill the engine mount hole then use all thread rods and cut the goofed up transom and clamp it together that way. It will be nice and even all the way across. I'll need to coat the bolts with something to keep them from sticking.

 

[Woodonglass]

Ok, did not realize it was an I/O!! That'll work GREAT. Vaseline works good as a release agent for the bolts.

 

[boat86fish]

Its an outboard. A mercury 115 hangs on it.

 

[Woodonglass]

Hmmm Ok well then the mounting holes are up kinda High and I'm still not sure how you plan on getting adequate clamping pressure down on the lower corners of the transom. Like I said it's kinda critical to get uniform pressure on the entire area of the transom to avoid delamination issues later on. All Thread 2x4's can only reach do so much and the more you tighten them the less pressure is applied towards the end of the board. You might want to consider building some transom clamps.