Reason for oval head screws on a Rich Line boat

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tlanders
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Joined: 10 Jul 2016, 15:28

Reason for oval head screws on a Rich Line boat

Post by tlanders » 10 Jul 2016, 17:09

I am rebuilding a Rich Line Boat with the Serial #590042 and is a Model C that I bought about 25 years ago. It leaks badly and the wood in the transom is all rotted out. It has the drain plug hole. I paid $60 for it when I got it. I just paid $75 for a sheet of 3/4" marine plywood to rebuild the transom!!! I am having a hard time finding the 1/4-20 x 2" aluminum oval head Phillips machine screws that bolt the transom together with. Broke a lot getting them apart. I can find slotted round head and Phillips flat head screws but no Phillip oval head screws. I am thinking of going with the round head screws and using an aluminum washer and some silicone - what do you think? Thanks for your help.

RazorBaits
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Johnny
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Reason for oval head screws on a Rich Line boat

Post by Johnny » 10 Jul 2016, 17:50

welcome aboard !!

most of us ditch the aluminum fasteners and go with stainless.
a lot less complicated - - - and readily available at most Big Box Stores.
http://www.tinboats.net/how-to-build-a-transom/
http://www.tinboats.net/varnish-vs-polyurethane/
All about Primers = http://www.tinboats.net/primer-and-paint-basics/
Paint, Thinners and Applications = http://www.paintingforpainters.com/

1959 Crestliner Commodore 14'
1959 Lone Star Malibu 14'
1958 Johnson 35 RDE-19 Sea Horse
1958 Johnson 35 RDS-20 Super Sea Horse

lckstckn2smknbrls
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Reason for oval head screws on a Rich Line boat

Post by lckstckn2smknbrls » 10 Jul 2016, 19:48

Silicone has an acid in it that is not combatable with aluminum.
1971 14' Ward's Sea King Jon Boat / 1983 Mariner 25HP

tlanders
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Joined: 10 Jul 2016, 15:28

Reason for oval head screws on a Rich Line boat

Post by tlanders » 12 Jul 2016, 12:29

Thanks for responding to my question. My company builds gas handling equipment for the bio-gas industry and we never allow aluminum and stainless components to touch each other - corrosion results because of the difference in the dielectric constant of the two materials. Have you seen any corrosion around the stainless fasteners to aluminum joints?

Thanks for the heads up on the silicone. I did buy a product called Amazing GOOP® Coat-It Epoxy to seal the rivets along the bottom. Has anyone used this product and how good is it?

Also, I have had conflicting information about welding the 57 year old aluminum. Some say that where you stop the weld, the metal becomes brittle because of the heat and a new crack will start there. Others say that is not a problem. The original weld in the corner where the transom is welded to the side panel has cracked. It's really a crack in the weld, not the base material, so maybe I could TIG weld it what do you think?

Teddy

weweber3
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Reason for oval head screws on a Rich Line boat

Post by weweber3 » 12 Jul 2016, 14:52

Johnny wrote:welcome aboard !!

most of us ditch the aluminum fasteners and go with stainless.
a lot less complicated - - - and readily available at most Big Box Stores.
No worries about aluminum to stainless steel contact and corrosion?

tlanders
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Joined: 10 Jul 2016, 15:28

Reason for oval head screws on a Rich Line boat

Post by tlanders » 12 Jul 2016, 17:14

If the contact is dry, no worries, it is just when the joint is wet that the dielectric voltage differential can conduct and create corrosion.

If silicone is not correct, what sealant material would be good for the round head screws and flat washers?

weweber3
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Reason for oval head screws on a Rich Line boat

Post by weweber3 » 12 Jul 2016, 17:35

I mean it's a boat, everything gets wet. However, my situation is the top rail area and transom area... all above water.

tlanders
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Reason for oval head screws on a Rich Line boat

Post by tlanders » 13 Jul 2016, 11:41

weweber3. I joined this group to ask questions not answer them!!?? I do have stainless to aluminum experience. Above the water line should not be a problem.

In liu of no responses to my questions yet, I welded the crack yesterday and it looks good. I am now power wire brushing all the rivet areas (400+ rivets!!!) and will apply the GOOP product unless someone says it won't work. The goop product is very expensive - $30 for 2# of it and it only covers 20 ft2. It is black. I would like to paint the rest of the bottom black so it will look nice. Can anyone tell me what is the best paint to use for this underwater aluminum situation? How about for the aluminum sides - what is the best paint to use?

weweber3
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Reason for oval head screws on a Rich Line boat

Post by weweber3 » 13 Jul 2016, 11:43

tlanders wrote:weweber3. I joined this group to ask questions not answer them!!?? I do have stainless to aluminum experience. Above the water line should not be a problem.

In liu of no responses to my questions yet, I welded the crack yesterday and it looks good. I am now power wire brushing all the rivet areas (400+ rivets!!!) and will apply the GOOP product unless someone says it won't work. The goop product is very expensive - $30 for 2# of it and it only covers 20 ft2. It is black. I would like to paint the rest of the bottom black so it will look nice. Can anyone tell me what is the best paint to use for this underwater aluminum situation? How about for the aluminum sides - what is the best paint to use?
Haha, I hear ya. I certainly am in the "ask more than answer" camp. Some day maybe I'll be helpful to others.

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