First post - rivets ?

[Ironhorse2022]

Hello everyone. Just brought home a 56 aero craft Lark yesterday and am starting to prioritize tasks. Several structural rivets (seats, not water sealing) need to be replaced. I have the typical pop rivet gun but suspect I need something better. As a new alum boat owner, should I invest in a different riveting tool ? If so, any brand / model suggestions ? Thanks !

 

[Ironhorse2022]

To clarify my request, I’m asking about blind rivets. I’m sure there are stronger ones available than the Home Depot type I have. Is it ok to use stainless rivets in alum boats. I know galvanic corrosion is a concern but can’t recall SS and alum specifically. I seem to recall that as long as the large part is alum and the small part is SS it’s ok. But maybe that’s the combo to avoid. I don’t know. Thanks.

 

[DaleH]

BLIND RIVETS:
FWIW I have had great success with 'high shear' high strength all-aluminum blind rivets, in limited applications! But they are of a 1/4" diameter, needed to get about the SAME strength as a 3/16" 1100F alloy solid set rivet. I'll have to take a picture of the box for you, but I got them from McMaster-Carr company.

Note you WILL need a large 'A'-frame rivet tool to set them.

I personally would never DIRECTLY apply or use SS on a tin boat, unless isloated. That is impossible to do with a blind rivet where the body and mandrel are of the different metals. Overtime the ions in tin will be eaten away, if SS is present, by the galvanic corrosion effects of dissimilar metals. I do use SS bolts through my tin hull, immersed 24/7 in saltwater, but I put a nylon washer under the bolt head and SS washer.

It works! I just checked a few cleats I put on a skiff ~10-years ago and the tin area around the SS fasteners was perfectly sound, and with no signs of any 'paint bubbling', which is a sure sign of the dissimilar metal effect to tin.

You didn't ask ... but as FYI or for others info:

SOLID RIVETS
1) Rivets
Most use 3/16" 'solid' body rivets

2) Where?
Buy in bulk from Jay-Cee Rivets, as they have a large inventory for great prices! See: https://www.rivetsonline.com/a187b0375a/a187b0375a
You want 'Brazier' head 1100F alloy 3/16" rivets, most likely in 3/8" length with a handful of 1/2" or perhaps even longer ones in case you need a few longer rivets, but if so, ALWAYS cut the length for best application.

3) Other
You need more tooling - see below, plus an air compressor and air hammer. On my old Starcraft with new transom 'skins' inside and out, as well as a new transom core, I put in over 300 rivets using a Harbor Freight pancake compressor and their air hammer tool (< $20). And many 100 since on other's boats too.

AIR HAMMER ANVIL SIZE - Here's a link to the proper tool to set brazier head riverts, using an air tool, for $10 to $13 ... at least when I posted those prices years ago now.

https://www.forum.tinboats.net/viewtopic.php?f=3&t=41248
BUCKING BAR - See link for this $20 bucking bar from VintageTrailer. I ordered it and had it 2-days later.

https://www.vintagetrailersupply.com/Bucking-Bar-p/vts-825.htm
You can use a scrap piece of metal for a bucking bar, but you DO NOT WANT a 'dimpled' bucking bar ... as you are bucking the TAIL end, not the rounded or dome-shaped Brazier head. You want a perfectly flat/square piece to bear up against the tail end of the rivet. And for best results, they must be held perpendicular to each other before AND while pulling the trigger.

 

[Ronbedard57]

Hello,
What a beauty! Dale's comments on rivets are spot on. I'd only use blind rivets where the originals were also blind. The tools for solid rivets are inexpensive, and the process is easy to learn. Have earmuffs for both you and the helper.
That instrument cluster on your dash is the same one that was on a '62 Hydrodyne I had years ago. Very cool.
You can really improve the clarity of that windshield with one of those graduated abrasive polishing kits for headlights. A good winter project. Have you researched whether the paint scheme is original? Looks awesome.
Good luck!
Ron

 

[Ironhorse2022]

Dale - thanks a lot for the detailed info - very helpful. I will start assembling those rivets and tools (already have a compressor).
Ron - what a gorgeous boat ! I plan to polish my non painted sections as well. I read that sharkhide is a good sealer to use to keep the luster. Do you use something for that purpose ? I’m not sure if the paint scheme is original but I like it a lot too. Unfortunately, up close, the paint job is horrendous (bubbles, alum show thru, etc) so just today, I started with the 220 grit to prep for some more coats. The base coat is Rustoleum topside. I’d prefer a urethane paint (rolled / tipped) but think I probably need to stick to the Rustoleum for compatibility reasons.

 

[Ironhorse2022]

Hey Ron. The original color scheme was anodized blue - see attached. I can still see this color on the underside of the bow cover. Would sure love to have it back but I guess paint is the practical solution.

 

[Ronbedard57]

Hi
Nice that you’re able to see the original paint scheme. I’ve had great luck with plain old rust oleum from the home center. You can’t get custom colors, but maybe that blue is pretty close to their stock blue.
I polish the hull with a pleated cloth wheel and a white clay bar. There are more aggressive clay bars if necessary.
I think you’ll probably polish first then mask those areas to do the painting. Looking forward to seeing the results.
Good luck

 

[Ironhorse2022]

Since there was no primer applied underneath the current coat of paint, I’ve decided to remove what’s left (50% there already) and use some aluminum primer (Rustoleum) first. Not looking forward to using stripper around all the rivets . I’ve used Magic brand paints before with very good success on small lawn tractors and figured I’d try it hear since their Ford blue is nearly identical to the original blue. Like Rustoleum, it’s an oil based enamel and has a hardener that can be added to toughen the paint. I realize I could custom mix the Rustoleum but like the idea of an of the shelf solution for touchups down the road. I’m going to try my hand at rolled and tipped . Was your aluminum originally anodized ? Mine is and although it’s all scratched up, it’s still rock hard and provides a fair amount of oxidation protection. Removing it commits me (and future owners) to a lifetime of polishing so I’m rethinking that step since it’s not reversible. Will probably still do it at least on the top decks.

 

[Ronbedard57]

Hi,
After polishing, I give a coat of Turtle wax. During the season, I wipe down with a beach towel and use some of that spray-on wipe-off stuff. Also by Turtle wax. Surprisingly, the worst offender for harming the shine is body oils. The "armrest" areas, and places where people may have sat develop a tarnish if not wiped down pretty quickly. This sounds like alot of effort, but wiping down the whole boat right to the waterline (mine is entirely a polished finish) takes about a half hour, and much less if I only address the visible spots. I'm about to winterize and cover, and I can see that the polishing in the spring won't be a big job at all. That's after a full season, with several daytrips in salt water. I think the highly polished surfaces oxidize more slowly because they're smoother, and we keep them waxed. The clay bars themselves have wax in them. (cant swear to this but I think so)
If I were you, and was going to remove that remaining paint, I'd be very tempted to polish the whole boat! If you go that route, I could offer a few tips on materials and process. Would love to see more shiny boats!

 

[Ronbedard57]

Hi again,
I thought someone would weigh in by now about how the boat sits on the trailer. The photo doesn't show whether there's room to shift the boat forward to get the transom supported. There's lots of info here about tuning up boat/trailer combos. I'm a big fan of bunks vs. rollers for lighter boats because it is easier to get that transom and motor weight supported. The trailer axles and winch pylon are adjustable on almost all trailers.
Its worth some thought if you'll be trailering very far.
Nice that you seem to have a garage to work in!
Ron

 

[Ironhorse2022]

 

[Ironhorse2022]

Hi Ron, good eye. Yes, the trailers a mess. It’s funny because in the sale add, the PO made a point to state how “dialed in” the trailer was. There are two or three rollers in the center to support the keel but there’s about 2” of air between them and the keel. Also, I just noticed today that the winch pylon can be moved forward allowing the transom to move forward. To get it home I used a brace between the lower unit and the trailer frame which actually fit great. I’ll be working on the trailer fit this winter.

 

[airshot]

The reason peopke have issues with SS rivets in aluminum has to do with cheap SS rivets. Not all SS is the same, some have a very low percentage of nickle which makes SS, stainless and corrosion resistantance. Like buying a SS kitchen sink, check it with a magnet...if it sticks the stainless will corrode. Good stainless will not adhere to a magnet and will not corrode !! Been actoolmake for 50 years and spent most of it working with stainlees steel, great stuff if you can find " real stainless" and not cheap wannabe stainless. When working with or around stainless, carry a magnet, if it sticks, walk away.
There are excellent quality tempered aluminum rivets that work extremely well, same as boat mfgrs use to assemble their aluminum boats. You wont go wrong using either materials as long as you dont buy cheap knockoffs..

 

[DaleH]

Good stainless will not adhere to a magnet and will not corrode !!

With all due respect ... you missed the point of this conversation ... we're talking about the effects on the tin.

While the SS will not corrode (maybe, see to follow), it WILL cause the tin to lose it ions due to the effect of dissimilar metals and the tin WILL CORRODE AWAY. This is what it looks like:



In regards to SSs and corrosion, ALL will ... if/when exposed to the right element or isolated from the preferred environment to preserve its integrity. Example, the truth is that one can still get 'crevice corrosion' on any SS bolt once trapped off from the oxygen. Look at the picture attached of a 3-year old SS bolt that was put through a frp glass boat transom. that is crevice corrosion. The lack of the passivated layer, protected by oxygen, is also one reason when cheaper 304-series SS will 'rust' (or bleed 'rust') when a higher grade 316L-series won't.



It, and other corrosion effects of metals, i.e., galvanic corrosion due to dissimilar metals, are also exacerbated and accelerated in the presence of an electrolyte, where saltwater is an ideal one (read as - it essentially forms a 'battery' between the 2 metals) as the salinity in that water type makes it an ideal electrolyte, i.e., it carries more electric potential. Is it that ePotential that eats or degrades the ions in the weaker or 'less noble' metal, hence the Table of Noble Metals (as noted in the 2800+ pages of the tome - Machinsts Handbook).

 

[airshot]

With all due respect ... you missed the point of this conversation ... we're talking about the effects on the tin.

While the SS will not corrode (maybe, see to follow), it WILL cause the tin to lose it ions due to the effect of dissimilar metals and the tin WILL CORRODE AWAY. This is what it looks like:

View attachment 112427

In regards to SSs and corrosion, ALL will ... if/when exposed to the right element or isolated from the preferred environment to preserve its integrity. Example, the truth is that one can still get 'crevice corrosion' on any SS bolt once trapped off from the oxygen. Look at the picture attached of a 3-year old SS bolt that was put through a frp glass boat transom. that is crevice corrosion. The lack of the passivated layer, protected by oxygen, is also one reason when cheaper 304-series SS will 'rust' (or bleed 'rust') when a higher grade 316L-series won't.

View attachment 112426

It, and other corrosion effects of metals, i.e., galvanic corrosion due to dissimilar metals, are also exacerbated and accelerated in the presence of an electrolyte, where saltwater is an ideal one (read as - it essentially forms a 'battery' between the 2 metals) as the salinity in that water type makes it an ideal electrolyte, i.e., it carries more electric potential. Is it that ePotential that eats or degrades the ions in the weaker or 'less noble' metal, hence the Table of Noble Metals (as noted in the 2800+ pages of the tome - Machinsts Handbook).

I have re-read the article a number of times and see no referencevto "tin" only questions about whether he can use SS or stainless rivets on his aluminum boat.