1979 Starcraft V5OB transom

[jasoutside]

Re: 1979 Starcraft V5OB transom

Notch trowel for TiteBond? Nah. Certainly for PL but a chip brush, cheap roller or straight trowel works great for TiteBond.

Cheers

 

[Yacht Dr.]

Re: 1979 Starcraft V5OB transom

So 1/8" notched will be too much then ?

I mean .. i can roller some contact cement way less then that ..

YD.

 

[bash11]

Re: 1979 Starcraft V5OB transom

I got the transom out today. It was in pretty bad shape. It was designed to be in three pieces so I was able to take it out without cutting or bending up the last 1.5 inches of gunwhale. Some of the threads mentioned making the replacement in one piece instead of three pieces. Is this necessary? Would it be that much stronger? I would think that Starcraft would have made it all one piece if it was necessary.

Thanks for all the information! I still have the above question (which was asked earlier in the thread). Does anyone know the advantages of making the transom like the factory (in three pieces) or make it in one piece?

 

[Woodonglass]

Re: 1979 Starcraft V5OB transom

Been working wood for over 40 years and doing large glue ups. I've use just about everything there is to spread various types of glue. Wood glue only requires a thin layer on both surfaces of even coverage to give a super strong bond as long as the clamping pressure is adequate and equal across the part being glued. This is prolly THE most critical aspect is equal pressure all over the surface area. Screwing the two pieces together with a 4" spacing is prolly the best method to ensure that your transom glue up is really glued up well.
But again for Large surfaces, pouring glue from a gallon container and using a 1/8" notched trowell to spread it quickly and evenly is a common practice in the shop. You can follow up with a roller if desired or putting the two pieces together and moving them around to evenly coat both surfaces. Proper clamping and a good even thin coat of glue on both surfaces IS the key to a good bond.

As for 1 or 3 pieces, If you can get it in in one piece, I'd think it would be best to make it in one piece. That's just my opinion.

 

[jasoutside]

Re: 1979 Starcraft V5OB transom

Yah, the one piece is stronger but for me the main reason is eliminating two seams on the transom where water would otherwise have somewhere to hang out, and lead to wood rot.

Keep on keepen on

 

[Yacht Dr.]

Re: 1979 Starcraft V5OB transom

Thanks for all the information! I still have the above question (which was asked earlier in the thread). Does anyone know the advantages of making the transom like the factory (in three pieces) or make it in one piece?

One piece lammed wood is going to be stronger for sure.

When you talk of 3 piece trans all I can think of is contour of the trans or ease of installation of the lamming in production. Is it strong enough with a 3 piece .. or a lammed 2 piece .. probably both/either will do in your case.

I would also suggest that you prep all the materials individually. Meaning when you prep alum you do it right ( fill fair, treat, prime and prep for the next application ).

When your bridging two different materials you should pay close attention to this aspect.

Glass on glass is easy .. going from alum to epoxy ( or whatever ) to wood is a different process which should follow different application guidelines.

I say that if you stick with epoxy ONLY when doing repairs with an Alum boat you will/should be better off then using poly/vinylester resins.

More questions or pics are required I think at this point is needed.

YD.

 

[jasoutside]

Re: 1979 Starcraft V5OB transom

When you talk of 3 piece trans all I can think of is contour of the trans or ease of installation .

Yah, when Starcraft built these boats the deck skin (gunwale tops) were installed first then the transom. By making it a 3 piece it was easy to install.

Now, since the gunwales are in place, you'll need to carefully bend them back (or carefully trim), then slide in the transom.

 

[bash11]

Re: 1979 Starcraft V5OB transom

Thanks again for all your opinions and suggestions. This gives me confidence that this project will be successful. I asked the following question a few weeks ago, but did not get an answer. Could someone(s) please give me some advice?

"I have some pitting on the inside of the aluminum. (The transom wood was original and not PT) Most pits are so small that they would not catch my fingernail, but there are a few that are about a half inch long and an eight to quarter inch wide. None of these large ones go in more than a half the thickness of the aluminum. There is also some white powder and rust colored stuff that comes off easily with a stainless steel wire brush. Are those pits good candidates for JB Weld? Do I put the weld on first or should I treat the Aluminum first? Should I spray it all with something like zinc chromate?"

What is the best way to stop the corrosion? Is brushing with a SS brush enough? What is the vinigar and water used for?

 

[jasoutside]

Re: 1979 Starcraft V5OB transom

By your description it doesn't sound too bad. So, a good cleaning and you should be fine. Skim with JB if you like.

A couple of photos posted up with what you are working on would be helpful, eh.

 

[Yacht Dr.]

Re: 1979 Starcraft V5OB transom

You need to treat the alum before filling or anything else.

I like to get a brass brush to scrub it .. then use some Alumiprep to "condition" it. As far as using Alodine after the Alumiprep is kinda up to you ( I would ) then yes put some Zinc Chromate over that.

The Vinegar is basically a DIY'ers way of not using the alumiprep/alodine way.

You can check this thread out http://forums.iboats.com/showthread.php?t=457159 for details if you like.

There are other products that do the same thing ( Im not suggesting that you use those products exclusively ).

YD.

 

[bash11]

Re: 1979 Starcraft V5OB transom

Attached are two pictures of the pitting on my inner transom skin. (There are no pits on the outside of the skin). The largest one is in the 2:00 position from the 1 inch splashwell drain hole. It is about about one half thickness deep. The other picture shows other smaller pits. The round hole in that picture is 3/8 inch diameter for reference.

I have some "Aluminum Cleaner" which contains proprietary "mineral acid". Will that work for the Alumiprep?

My goal here is to stop the corrosion. I plan to leave it unpainted. I was told by someone at work that if I treat only part of the aluminum with Zinc chromate, then the untreated areas are more suseptable to corrosion due to the concentration of galvanic action. Have you found this to be the case? Would I be better off to stop the corrosion and let the aluminum oxide form and protect the surface? The plywood transom which will be in contact with it will be protected with 3 coats of epoxy.

Thanks in advance,

Bash11

 

[bash11]

Re: 1979 Starcraft V5OB transom

I have the new transom cut out and ready to glue it up. I noticed that there is a slight crown on my Aluminum skin (about 3/8 inch outward in the middle). Should I glue the two transom boards so they are perfectly flat and force the aluminum skin to conform to it or should I try and put a 3/8 inch bow in it.

Also could someone please answer my previous October 13 post.

Thanks in advance,

Bash11

 

[Woodonglass]

Re: 1979 Starcraft V5OB transom

if the Bow in your transom is supposed to be there then it's advisable to fabricate the new transom to conform to that shape. Not a "Tinny" owner so can't offer answer to your 10/13 post.

 

[djpeters]

Re: 1979 Starcraft V5OB transom

I have the 22' version of your boat. My transom is dead flat, no crown. It'd be safe to say yours should be flat too.

I'm not a corrosion expert...sorry.

 

[jasoutside]

Re: 1979 Starcraft V5OB transom

Should I glue the two transom boards so they are perfectly flat and force the aluminum skin to conform to it

Yes

Likely that "crown" got there as a result of a mushy transom.

That "crown" on my Sea Nymph was HUGE! Like 3 feet!! Well, exaggeration. But it was way out there, like maybe more than an inch.

 

[Yacht Dr.]

Re: 1979 Starcraft V5OB transom

I have some "Aluminum Cleaner" which contains proprietary "mineral acid". Will that work for the Alumiprep?

My goal here is to stop the corrosion. I plan to leave it unpainted. I was told by someone at work that if I treat only part of the aluminum with Zinc chromate, then the untreated areas are more suseptable to corrosion due to the concentration of galvanic action. Have you found this to be the case? Would I be better off to stop the corrosion and let the aluminum oxide form and protect the surface? The plywood transom which will be in contact with it will be protected with 3 coats of epoxy.

Thanks in advance,

Bash11

I dont know if your alum cleaner will be as affective as alumaprep/alodine/ZC. But Its gotta be better then just wiping it down with some acetone or whatever.

YD.

 

[bash11]

Re: 1979 Starcraft V5OB transom

My transom is all glued together and ready to coat. I have a question about 5200 and hole size. Would it be advisable to make the holes in the transom wood 1/32 inch or so larger than the fastener and then try and coat the inside of the hole with epoxy? This could act as a second line of defense against water penetration.

When the fasteners are installed, do you put the 5200 just under the screw head or do you coat the shaft too? How permanent is the 5200? Can the fasteners be easily removed in the future if needed?

I will need to cut my aluminum splashwell tubes to the right length. How much should I allow for the flare? If the thickness of the outer skin+wood+splashwell is 1 and 5/8 inch, What length should I cut the tube (which already has a flair on one end)?

On the aluminum pits, should I put the Alumiprep/Alodine down before or after the JBweld in the pitted areas? Using it before the JBweld makes more sense to me, but some of the posts that I read were unclear.

Thanks,

Bash11

 

[bash11]

Re: 1979 Starcraft V5OB transom

Hi,
I am starting to assemble my boat now.

What is the shelf life of 4200 after the caulk tube is opened? I know that the directions say 48 hours, but this seems a bit short. Is there a way to extend the shelf life (like storing in a vacuum bag or in a colder place). How do I know when the shelf life is exceeded? If it is still sticky is it still good?

When the fasteners are installed, do you put the 4200 just under the screw head or do you coat the shaft too? How permanent is the 4200? Can the fasteners be easily removed in the future if needed?

Thanks,

Bash11

 

[64osby]

Re: 1979 Starcraft V5OB transom

Bash, Nice looking boat. Just saw your progress on the transom.

Some here freeze the tube and say it adds lots of shelf life. Just have to cut down the end or make a new opening over time.

If your putting in screws get some under the head and a little on the threads, you want to try and seal the hole as much as possible.

4200 is not "permanent" it stays flexible. Easily removed is a matter of opinion.

Were close neighbors as far as iboat members go if you're near Coloma.

 

[richardlee]

Re: 1979 Starcraft V5OB transom

I got the transom out today. It was in pretty bad shape. It was designed to be in three pieces so I was able to take it out without cutting or bending up the last 1.5 inches of gunwhale. Some of the threads mentioned making the replacement in one piece instead of three pieces. Is this necessary? Would it be that much stronger? I would think that Starcraft would have made it all one piece if it was necessary.

I have some pitting on the inside of the aluminum. (The transom wood was original and not PT) Most pits are so small that they would not catch my fingernail, but there are a few that are about a half inch long and an eight to quarter inch wide. None of these large ones go in more than a half the thickness of the aluminum. There is also some white powder and rust colored stuff that comes off easily with a stainless steel wire brush. Are those pits good candidates for JB Weld? Do I put the weld on first or should I treat the Aluminum first? Should I spray it all with something like zinc chromate?

How much Titebond III will it take to properly glue up the transom? Do I put a thin even layer on the wood or should I use a notched trowel? How much epoxy should I need to coat it? It is about 16 square feet in area.

Where can I get replacement drain tubes for the splashwell?

I really appreciate all your help,

Bash11

I replaced my transom with a 1 piece. Glued 2 sheets of 3/4 plywood. Had to bend up the side pieces to drop in. Epoxied all wood and used epoxy inside bolt holes. Also used M 5200 caulk.