2024 Anything new for laminating a transom?

[Pale_Horse_Idaho]

Hello from N Idaho...

Can I run down what I have and what I want to do and get some advice?

14ft Mirrocraft Deep fisherman.
1.5" thick 53 in wide 12" tall 50+ year old untreated unsealed unpainted transom. Amazing it held up this long!
New 4x8 actual 3/4 inch A/B Marine plywood ($165.00) special order Home Depot, no one carries this anymore.

What is the best 2024 easily obtainable laminating glue? If not easily obtainable then what is the best. (Ive seen wood glue get wet after it dries and it turns white and soft again)

I do not have clamps so can I just have my wife stand on it for 24hrs? Just kidding!

Can I use screws instead of clamps? What type? What coating and MOST IMPORTANT would I want a 3/4" bare non-threaded shank on top half followed by the screwed section on bottom so they don't push the wood apart?

Can I leave the screws in after bonding layers?

Once laminated what is the best outer coating and edge seal?

Do I want to put anything between the rear aluminum boat skin and wood transom? The old one had nothing.

Is it OK to use stainless bolts for the knee screw brackets? Dissimilar metals?

I want to put a heavy duty clamp plate on the outside and inside as the 25hp is rough on the boat skin. Should I bond these to the wood before outside coating or after?

Where can I buy the top trim? Looked at a few online sites and cannot find this size.

Thanks for the help. I don't want to have to do this again so first time right time kind of thing.





Where do I buy this dimension C Channel aluminum?

 

[LDUBS]

Welcome to the forum!

My two cents:

Laminating/sealing transom ply:

You can use epoxy resin to laminate the two pieces of ply together. Use any 1 1/4" wood screws you have around to "clamp" them while drying. Remove the screws and fill the screw holes with epoxy resin (I would not leave the screws in). Coat the completed transom with epoxy resin. If you use the wife to stand on the assembly, don't get glue on her shoes -- unless you want them as a permanent fixture.

Do I want to put anything between the rear aluminum boat skin and wood transom? The old one had nothing.

I think you mean a coating of some kind on the aluminum skin? I would say no.

Is it OK to use stainless bolts for the knee screw brackets? Dissimilar metals?

Use solid aluminum rivets instead.

I want to put a heavy duty clamp plate on the outside and inside as the 25hp is rough on the boat skin. Should I bond these to the wood before outside coating or after?

I think you mean a transom pad. A wood transom pad will help the motor clamps bite. I personally would seal the pad before installing it. If you are using a bolt on motor, then a pad isn't needed, IMO. If you are putting a sacrificial pad on the inside of the transom, I would not adhere it to the transom wood. If you do, it is no longer "sacrificial".

Top Trim?

Do you mean the cap or pictured C-channel that covers the transom wood? Likely not going to find what you pictured on the on-line sites (they will have sharp cornered channel). Looks like you need 1.75" wide with 1/16" thickness. I would check with a local metal fabricator. Or, clean-up and reuse the one you have.

 

[Pale_Horse_Idaho]

OK I bought Wes 105 and 206 hardener. I got the transon cut out today. Going to laminate tomorrow.

Can I use the Wes 105 to coat the exterior of the transom as well as I will have enough leftover.

 

[FuzzyGrub]

For glueing the two 3/4" pieces togeter, I've used Titebond III (waterproof), available just about anywhere, Clamps are cheap at Harbor Frieght and superior to screws. I used 5 gal pails filled with water (or sand) in the center section where clamps don't reach well. Doesn't look that would be neccessary with yours. I treated the transom wood and coated the inside of the aluminum to create a barrier against corrosion. I used Glu-vit but your epoxy coatings should be fine. If you leave the face exposed, most epoxies need to be painted to prevent break-down from UV. You will never have to replace that transom again in your lifetime.

 

[LDUBS]

I think the West Systems 105 would be an excellent sealer for the ply, and especially if you have it on hand. But note @FuzzyGrub 's caution about painting it for UV protection.

 

[Pale_Horse_Idaho]

OK, thanks guys

I just got the 2 parts laminated and used 2 screws at each end to keep it from sliding out of place. Then put everything I had in the house on it to clamp it. After the epoxy lamination is done I plan to use a horse syringe to fill the little pocket holes around the edges. Once filled I will put green frog tape to hold it in.

Looks like I used 205 hardener and at room temp (70f) the 8oz pot lasted 20mins before it started to harden. Much longer then the 8-12 stated on the can. And DANG it got hot. It was smoking and ready to melt the mixing cup.

I will keep posting progress reports until finished. Thanks again.

 

[Pale_Horse_Idaho]

Well I officially laminated the Idaho Nickles Worth newspaper to the back of my transom. DOH! Took me 20 minutes to sand off. Have it primered now and ready to top paint. Raining here now so will have to wait for more optimal humidity.

 

[airshot]

That 14' Mirro makes a great platform, I owned one back in 1964, great boat, never an issue with it. Yours should fly with a 25 on it, we had an 18 up and skied with it !! Looking forward to the finished pics...

 

[Pale_Horse_Idaho]

That 14' Mirro makes a great platform, I owned one back in 1964, great boat, never an issue with it. Yours should fly with a 25 on it, we had an 18 up and skied with it !! Looking forward to the finished pics...

It does 30mph on calm water with an 11 1/4 pitch prop. It would probably go faster but I installed plywood floors and it adds weight.

 

[airshot]

Watch your rpm and make sure your engine is running at its peak with that prop.

 

[Pale_Horse_Idaho]

Watch your rpm and make sure your engine is running at its peak with that prop.

It does 58-5900 with me and the dog. Add the wife and an ice chest and I have to drop down to the 10 3/4 prop to maintain 5850. If I don't it drops to 55-5600. Somebody needs to make a 2 speed lower unit so you don't have to swap props. I wonder if painting the bottom of the boat with Teflon or a hydrophobic paint would give me another 5mph?

 

[FuzzyGrub]

Somebody needs to make a 2 speed lower unit so you don't have to swap props.

I do recall a pitch changing prop. Low pitch on take-off, then would "shift" to higher pitch. It was for larger boats. Never seen allot of people running it. Probably some issue or too costly.

 

[thill]

With a small engine, you just have to choose. I used one prop when alone and a lower one when others were with me. Just part of the game

 

[Pale_Horse_Idaho]

I do recall a pitch changing prop. Low pitch on take-off, then would "shift" to higher pitch. It was for larger boats. Never seen allot of people running it. Probably some issue or too costly.

When I used to fly with my buddy that had 7 differnet airplanes he had one that had a variable pitch prop. I think there were 2 types. One would adjust itself according to rpms and the other was a manual adjust from the cockpit. They were expensive and prone to fluid leakage.

Snowing today so no progress on boat...

 

[farmer4life]

Nice boat! I have a 1968 of the same make and model that I redid last year, including a transom. Your transom compression solution is a good idea but I don't know if it will be as effective as clamps. You do have a lot of weight on there, but with clamps you can apply much more pressure. Those battery boxes might be 60-80 lbs over their face area but a clamp can apply 100's of lbs per square inch. Of course most clamp surface areas are about 1 sq. inch anyway so that force will spread out through the wood. Maybe it amounts to the same thing in the end. I still prefer the clamps. I have a growing collection and it still never seems like enough

 

[LDUBS]

Nice boat! I have a 1968 of the same make and model that I redid last year, including a transom. Your transom compression solution is a good idea but I don't know if it will be as effective as clamps. You do have a lot of weight on there, but with clamps you can apply much more pressure. Those battery boxes might be 60-80 lbs over their face area but a clamp can apply 100's of lbs per square inch. Of course most clamp surface areas are about 1 sq. inch anyway so that force will spread out through the wood. Maybe it amounts to the same thing in the end. I still prefer the clamps. I have a growing collection and it still never seems like enough

Can never have too many clamps. For things like that I use clamping cauls. For this kind of project, with epoxy on hand, I would simply screw the two together. Remove the screws when dry and fill the holes with epoxy.

 

[Pale_Horse_Idaho]

Got the inside of the boat painted today where the transom goes. It had rubbed raw and slight oxidization I primered and painted today as the sun was out. Its been very cold here for painting. The new transom wood now has 2 coats of oil based top coat paint. I cheaped out and skipped the 2 part paints at 100 per.

I was able to get a local metal fab shop to cut and bend the new trim and screw plate for motor.

Question:

Is it better to clamp the new transom in place and drill holes through the wood and line up with existing metal skin holes. Or lay old transom on new and drill holes?

I only get one shot at this to be right.

 

[thill]

Definitely line up with the metal skin and drill. Just have a shop vac handy to clean up the chips.

If they drilled the old transom holes at an angle, it might not work out if you use the old wood as a guide.

 

[Pale_Horse_Idaho]

Definitely line up with the metal skin and drill. Just have a shop vac handy to clean up the chips.

If they drilled the old transom holes at an angle, it might not work out if you use the old wood as a guide.

Angle, good point. Thats why I asked first. Measure twice cut once.

 

[Pale_Horse_Idaho]

OK, made some progress today. Tried to insert transom yesterday and found that the old piece was bowed. The straight piece did NOT want to go into the already tight as heck gap between back of boat and knee braces. Soooo I improvised. I wedged one side in and then angled the other down and used a big screw driver to pry the other side into place all without doing any damage to the board. The new painted transom took a few scratches that I can touch up easy enough. I noticed the knee brace holes to go through at an angle so glad I didnt lay old transom on new and drill holes.

Shop bending new trim got 2 of the pieces done. The top trim and inside transom to motor protection. The outside piece is being made today. Cost to have trim made was about 130. The pictures show the inside motor transom trim piece on the outside so I could take a picture. The top trim need to be bent to the transom. I will shape it on the old one so as not to damage paint on new one. I bought a map torch and got all the stainless hardware to bolt it back together. I getting close now. Maybe 2-3 more days. Weather here has turned nice for the last few days. It is 70f today and the snow is mostly melted. Other boaters are catching trout on the lake and I want to get out there.