21.5' 1990 Campion Fishing machine transom and stringer restore

[j_k_bisson]

Re: 21.5' 1990 Campion Fishing machine transom and stringer restore

Quick pic to give you the ideaView attachment 83256

Trace the cap curvature on a piece of plywood and cut out. Might need to make a double thickness for strength. Use the holes along the top edge where the rub rail was attached to screw it to the hull. If you have holes.

 

[mcgyver]

Re: 21.5' 1990 Campion Fishing machine transom and stringer restore

ThanksJeff, my biggest concern now is the curve in the transom. This curve has to be perfect to mate with the cap.
Doug

 

[j_k_bisson]

Re: 21.5' 1990 Campion Fishing machine transom and stringer restore

Don't do anything tonight. Sit back and have a couple of beers in the boat making motor noises and think about it. If any question ask away. Worst that will happen is no response and a head ache in the morning...... LOL Did that a couple time on this project soo far. I'm sure you will too!

Oh yah I like taking 2 Advil liguid gel caps 400mg for the head aches. They take about 20min to kick in......... Then I ready for the day...... Also the pickyness stops a bit......

 

[mcgyver]

Re: 21.5' 1990 Campion Fishing machine transom and stringer restore

Jeff, i think we posted at the same time! I saw the pic in your thread about the 3 pieces. Was the transom built that way from factory? It looks like with mine that there are no knees coming off the stringers to add support to the transom. I would be concerned hanging a 150 off the back end with a cut up transom. How did campion do it? and yes i agree that the ply "would" bend, but it inherantly wants to go back to straight and therefore would pull the sKin with it and i'd be pooched, majority flat transom. Arghhhhh!!!!!!!

 

[mcgyver]

Re: 21.5' 1990 Campion Fishing machine transom and stringer restore

Found this quote while searching the forum



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Join Date:May 2009
Location:Stanwood, WA
Posts:912 Re: 1985 bayliner transom
Originally Posted by CTS 10/63
My transom is similar. It has three seperate pieces. I don't understand how it is structurall sound enough to hold the motor. If I replace the center board how do I cement it to the outside skin? The interior side is falling apart. Do I re-glass the inside once the new wood is in place?

CTS
The whole transom should be replaced as ONE PIECE. The whole point of a transom is to distribute the weight/force of the motor evenly over the whole transom. A 3 piece transom will not distribute weight like it should.

Jeff, you are the engineer...... the whole piece senario makes sense to me, but I don't have an engineering background....regarding the 3 piece

Doug

 

[j_k_bisson]

Re: 21.5' 1990 Campion Fishing machine transom and stringer restore

Ok in the engineering sense, at the factory I would use multiple layesr of ply, 1/4-3/8" and have a metal (hydraulic press) glue jig that is shaped the same curvature as the hull is required to be. The I would laminate/glue and bend/warp the different muli layers of ply with force, heat, steam, and glue. Basically preforming the wood for the transom to what I wanted. Then cut to shape. Seeing you do not have the jig or hydralic press to bend yours, I would go the three separate pieces method.

Mine came from the factory with a three piece construction. Most of the bayliner from the 80's and 90's where done this way. And the transom issues with Bayliners where not due to this three piece constuction system. It was because they did not seal the transom after drilling all the holes in it. So water intruded into the wood and rotted them.

Your champion had one piece from what I can tell from your pics. Seeing you do not have the capability of replicating the factory piece of wood. You are going to have to go the three piece method. IMO

Is it strong enough to hold a 150? Yes if you ensure that stringers and gussets are in place to aid in the structural aspecs of the system you are building. No transom is one piece. They are built out of multiple piece glassed together. The stringers and gusset must be glassed to the hull and transom to become a transom system. Even if you are not going with a three piece design, I would do the gussets and stringers to the best (strusturally) you can. Never hurts to have a strong back bone in a boat! Bring the stringer and gussets as high as you can on the transom. The added hieght will increase your strength by astronomical amounts. Hell Bayline 2302 hang's twin 150hp Forces off transoms with this method of construction.

My sugestion to you is draw up a sketch like the one I had done in my rebuild, put some rough numbers/dimensions to it. Try to show a before and after. Then open a new thread here on Iboats with a weird title and have everyone shot holes in it. Include a few pics on the hull and stringers as it was and as it is now when you do it. That way you will get more exposure to your idea's. And then the experts will start chiming in. Also it will not be in your log thread here with all of your progress on your project.

 

[j_k_bisson]

Re: 21.5' 1990 Campion Fishing machine transom and stringer restore

Here is a couple of sketches of what I was talking about last night.

 

[mcgyver]

Re: 21.5' 1990 Campion Fishing machine transom and stringer restore

Wow, thanks Jeff. The 2 vertical "joints" where the 3 panels meet...do you fill that gap? and then 1708 over the whole transom as usual? The gussets wont be a problem (have to check for room from the deck). Anyways thanks again.
Doug

 

[j_k_bisson]

Re: 21.5' 1990 Campion Fishing machine transom and stringer restore

I would get the center piece in first then the stringers. Both glued and tabbed. I would "fit" in the side pieces in nice and tight then glue and tab them. Yes I would use 1708 where ever you can. It won't hurt anything but you pocket book! lol

 

[mcgyver]

Re: 21.5' 1990 Campion Fishing machine transom and stringer restore

Thanks Jeff, downed a couple of beers while holding my trusty tape measure this afternoon (that helped!). Gusseting the stringers will work with the room i have but how high up that center transom piece the the gusset would be a minimum for the strength requirement (engineering perspectice) I know I need to go as high as possible but may run into problems when the splashwell and cap go back down and i want to account for that. things are very tight fitting ie battery boxes ect and i'll be measuring 3 times to make sure it will all fit. thanks again
Doug

 

[j_k_bisson]

Re: 21.5' 1990 Campion Fishing machine transom and stringer restore

I stayed a 1' from the splay well under side. Also if you need to run wiring ans stuff through there, You can allways drill holes through it and re seal it up. As long as the hole is not too big.

 

[mcgyver]

Re: 21.5' 1990 Campion Fishing machine transom and stringer restore

I'm debating putting 2 more gussets as you did in your install and what was original with bayliner. problem is that I won't be able to put a 90 degree board to tab into...the tabbing will come strictly off the hull (did that make sense?) Do you think it is needed with the 3 baord transom configuration...as always bigger is better but if i can save a step and it's not needed. Can't find any other pics of transoms that are built from 3 like the bayliner.
Doug

 

[nemo2011]

Re: 21.5' 1990 Campion Fishing machine transom and stringer restore

Was your top held down with screws or pop rivets?

 

[j_k_bisson]

Re: 21.5' 1990 Campion Fishing machine transom and stringer restore

I'm debating putting 2 more gussets as you did in your install and what was original with bayliner. problem is that I won't be able to put a 90 degree board to tab into...the tabbing will come strictly off the hull (did that make sense?) Do you think it is needed with the 3 baord transom configuration...as always bigger is better but if i can save a step and it's not needed. Can't find any other pics of transoms that are built from 3 like the bayliner.
Doug

The more the marrier for gussets. If your transom did not have them don't feel you need to add them. But they would help alot. Do you have a pic of you floor before you started. How about instead of the 90'deg board like I had a center stringer extends say 4-5 ft forward, or maybe two extra stringer untill you hit the gas tank. Then a cross board at the tank.

Just an idea. You can do what ever you want right now. Deffinately make it better. You are not restricted by a budget of material, workers hours, and profit margins like the factory was/is. So make it the best you can.

 

[mcgyver]

Re: 21.5' 1990 Campion Fishing machine transom and stringer restore

Nemo...175 rivets...

Jeff - my concern comes from the fact that i am changing the "design" of the transom from a 1.5" complete solid transom that was tabbed to the sides of the hull to a 3 piece transom design. i'm concerned that I lose some engineering stability where the 2 vertical cuts are on either side of the middle transom and only going to 3/4" ply on the 2 side pieces. The original stringers only extended up the transom 8" on the original (not even 1/2 way) Am I overthinking this thing, will the 2 lateral stringers with gussets that extend to within 5" of the top of the transom be enough structuaral strength? I don't want to be under supported but don't need to build too big of a tank!

Thanks for the thoughts though... hows the engine restore coming?
Doug

 

[Spiketop]

Re: 21.5' 1990 Campion Fishing machine transom and stringer restore

Hello Mcgyver, The three piece transom idea makes me nervous. I don't know quite how much transom curvature you are dealing with but if it is not too extreme you may be able to shape the back of your first piece of plywood to fit the curve of the transom. This would give you a flat section for the next piece of ply to fit to. The second sheet would also have to be shaped where it extends beyond the first sheet. If the curvature is 1" overall you would end up with a transom that is 1.5" thick in the center and.5" where it meets the hull sides. A lot of fitting but at least you would get away from the dubious three piece transom( another of Bayliners better ideas?). JB

 

[Woodonglass]

Re: 21.5' 1990 Campion Fishing machine transom and stringer restore

GUYS!

You can Laminate that Curved transom, using 1/4" ply, resin, mat and transom clamps. Cost you about $50 bucks (10 bucks each) to make em, but they come in real handy. I showed em to a guy last summer and he used em on his boat. Here's a pic. I have since changed the design a bit so now you just use large bolts instead of All Thread. You might have enug scrap wood and bolts to make em for nuthin. Work great!!