PDA

View Full Version : Pop Rivets (Sheet Metal Boats)


Bud
05-23-2004, 04:20 PM
Pricer, I havce an article from the boat div. Of The Mullins MFG Corp, This was one of your questions on rivets and spacing or were you wondering size of rivets?

This response is from the readers information exchange. The article is titled "Tight - Seaming Sheet metal Boats" and goes on to read;

In our galvanized sheet iron boats, we use a counter sunk flush joint, rivetted, with rivets spaced 3/4 in. apart, these joints are then float soldered. We find this to be one of the most satisfactory seams or joints to make in a boat.
In our aluminum boats, we weld all the seams and have found this quit satisfactory.

Source January 10 1930 Sheet Metal Worker

Bud

pricer
05-23-2004, 05:08 PM
How in the world do you find all of these things? Was this something from your library? I understand that they are reffering to a "real" rivets, do you think I could use closed pop rivets in this project? When they are talking about,"float soldered" what does this mean?

Thanks,

Grue
05-23-2004, 07:03 PM
Pricer,

To get a waterproof joint, the "sphere of influence" of the rivets must overlap. From memory, the sphere of influence of a rivet is 4D. This means that if you were to use 1/8" rivets, you would have to use a rivet spacing of 3/4" to get the seal you require. With 20 gauge material you would have to dimple countersink the rivets to get a flush fit. You would need over 500 rivets just to rivet the bottom to the frame.

I would suggest that 1/8" would be too big as the usual formula for rivet size is 4 times the thickness of the thickest sheet being joined. 3/32" rivets would be a better size. This of course would reduce the pitch of the rivet to 5/8" , about 600 rivets. You'd still have to dimple for a flush fit.

So the cost is really going up now. You'll need maybe 100 or more skin pins to hold the bottom onto the frame while you drill all the holes and maintain alignment. I'd go for Avdel pins rather than Cleco. There are some clecos on ebay http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&item=2479211951&category=26436

The countersink in the frame is easier with a "cage" you can set the depth of the countersink accurately. Again on ebay
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=2479196965&category=26436

Food for thought.

Grue

Bud
05-23-2004, 09:29 PM
How in the world do you find all of these things? Was this something from your library? I understand that they are reffering to a "real" rivets, do you think I could use closed pop rivets in this project? When they are talking about,"float soldered" what does this mean?

Thanks,

Yes I have quite an extensive library, that in time all will be able to enjoy. It's "The Sheet Metal Shop Resource Center" Hence the name resource :)

I have been looking into this "Float Soldered" term? I'll put it here as soon as I find a proper explaination.

Bud

pricer
05-24-2004, 06:27 AM
Thanks for the help. I am very happy to see this forum. Thanks Bud. I have not found anything on the topic of "float soldering". Thanks again.

marky
05-24-2004, 10:57 AM
I dont know if this is of any help but when we used to make water tanks for life boats some of the older type before lockformed edges were rivetted,to repair them we had to take out the old rivets and replace with new,these were counter sunk copper or tinmans after they had been drawn and set the rivets were tinned and then sweated to make them watertight.aw ra best marky

pricer
05-24-2004, 05:40 PM
How does the countersink cage work? Does it attach to something or is it hammer driven?

Grue
05-24-2004, 05:54 PM
Best way to describe it is that its part if the drill bit, you can adjust the depth that the drill goes into the material very accurately. Once adjusted you can drill or countersink multiple holes to an identical depth. They are used extensively in aircraft manufacture / repair.

Glenn

pricer
05-24-2004, 10:02 PM
Grue,

I went to ebay and the seller of the cage you mentioned has, 3 Zephyr Countersink Cages w/15 Bits . Is this a good brand?

Thanks,

SteveB
05-26-2004, 08:21 PM
Pricer,
The Zephyr countersink is a really good tool.
I picked one up years ago for $5.00 at a local swap meet. They're generally used in Aircraft work. They're adjustable by the 1000th's.
I'd think you could find one on Ebay.
I used mine when construction work was slow, and did sign work. The boss had one, and spoke very highly of them. So, I went out and bought one.

pricer
05-29-2004, 08:39 PM
Thanks steveb, I will go se how the bidding is going.

SteveB
05-30-2004, 09:08 PM
Pricer,
Did you win the bid?
Sounds like it would've been a good deal.
SteveB.

pricer
05-30-2004, 10:03 PM
I did purchase the cage and I have bids on another one. I think it was a good deal. Wha do they sell for new?

SteveB
05-30-2004, 10:16 PM
That was why I gave you the site address.
I think they cost upwards of 100.00 each. It's been so long, I really can't remember anymore. I bought mine back in 92.

SteveB
05-30-2004, 10:24 PM
Pricer
If I were you, I'd buy all of the offered one's including the one's from Australia.
If you have the cash.
Those prices are worth it. Especially the one's for 22.00. If you win, you've got a good deal, for certain.
SteveB.

pricer
05-30-2004, 10:24 PM
With shipping it was $19.00. Great deal I hope, it will be the first transaction at ebay.

SteveB
05-30-2004, 10:52 PM
19.00 is an excellent price. Good deal.
Remember, those are precision tools. Precision tools are never inexpensive.

Grue
05-31-2004, 12:15 AM
Pricer,

This sort of thing comes up at Boeing surplus sales you can buy there at the same price as the ebay sellers buy.

Glenn

pricer
05-31-2004, 02:41 AM
The cage I purchased, Is it capable of drilling 3/32 rivets? Are the bits interchangable?

SteveB
05-31-2004, 08:12 PM
Drilling rivets? They do have a rivet shaver, which will remove the rivet heads. Yes, the bits are interchangeable. The shavers will allow you to remove the heads and pull the rivet out from the rear. Or just punch it out with another rivet. A pretty smart idea actually.
Enjoy. You got an excellent tool.

pricer
05-31-2004, 08:15 PM
Thanks, hat do you know about Cleco pins? Did I say that right? I get the feeling that I may need a few.

SteveB
05-31-2004, 08:36 PM
Cleco's are an excellent tool for holding metal in place while setting for up riveting multiples.
Go for it. That too is a good tool to have.
I remember seeing them for years, and thinking-- naw, not worth the $$. I then saw a fellow mechanic use one for metal roofing flashings. I then had to ask. He told me that he swears by them, and wouldn't be caught dead without his. That was enough for me.
That also is something you should be able to get off of Ebay. If not, go to the web site that I'd sent you.
Again.... not an inexpensive tool if you get them brand new.
Since you're going for the high end tools, another tool of value-- for many things, os the short reach right angle drill. They are made by an outfit here where I live-- about 9 miles north of me.
United Air Tool.
PM me, and I'll give you the link.
If Bud approves it, go ahead and post the one that I send you.
I used this mechanics' that I mentioned above for doing tight rain gutter. Talk about a sweet deal. I previously used a 6"- 12" #30 bit to drill through both the front and back of the gutter-- at the same time. This short reach angle drill allowed me to drill only the back.
Again.... a pricy tool. They start out at $100 and up. Ebay might have one. Ok, I've looked on Ebay. They do have some, but not the same one's as I'm talking about.
I typed in "aviation angle drill."
Good luck.

pricer
05-31-2004, 08:57 PM
Thanks for all the help. I am sure I will have more questions just give me time. LOL

Grue
06-01-2004, 05:01 PM
Pricer,

The Clecos hold the panels together with spring tension inside the pin. There is another type made by Avdel. You don't need a special installing tool as there is a little thumb wheel on them to apply the closing pressure. They are a little more time consuming but give a positive tight join.

Grue

pricer
06-03-2004, 05:31 PM
Hello All, My countersink cages came in today. I did not realize it but I have purcased three. They are of very high quality, they do not have bits. Where would I buy the bits? Mobile Aerospace is in my town, they refurbish large commercial aircraft. There should be an air craft supply place near me. I will need to dig into it tommorow. Are the bits universal? I understand how it is ajusted. It looks like the bits thread into the cage.

Grue
06-03-2004, 06:36 PM
Pricer,

The bits are usually standard 1/4" shank.

Grue

pricer
06-03-2004, 07:53 PM
What is the best and most accurate way to layout the pitch of a rivet. Would it be to take a narrow strip of metal and drill a series of holes that represent the pitch? Clamp the jig plate onto the part and use a prick punch to mark the holes?

One of the counter sink cages looks like it has 3/8" threads and the two small ones have 1/4" threads.

Grue
06-03-2004, 11:58 PM
Price,

The main problem is accumulative error. With the type of work you are doing the method you suggest would work fine. Most of the guys that do this all the time mark the ends and work towards the centre using a pair of dividers, measure the overall every foot or so and adjust the dividers to take out the error.

Grue