Re: Self tapping vs. wood screws
i have had good luck using drywall screws building flat bottom
plywood boats with epoxy encapsulation, both leaving them in and
taking them out after the underlying glue is dry. any screw sticking
all the way through into the interior will easily break off with vise
grips. they do have to be countersunk down in the wood enough so they
dont raise the epoxy glass and make a place that will strike a bottom
rock and create a waterway into the hull wood. that would be my main
reason for wanting to remove them. however a powerdrill/screwbit will
sink them deep enough.
bill
plywood boats with epoxy encapsulation, both leaving them in and
taking them out after the underlying glue is dry. any screw sticking
all the way through into the interior will easily break off with vise
grips. they do have to be countersunk down in the wood enough so they
dont raise the epoxy glass and make a place that will strike a bottom
rock and create a waterway into the hull wood. that would be my main
reason for wanting to remove them. however a powerdrill/screwbit will
sink them deep enough.
bill
--- Inbolger@yahoogroups.com, "sanmi" <sanmi@y...> wrote:
> I've been using some swiss cabinet screws around the house that are
> self drilling and made for wood. Look kind of like drywall screws
> but are much more expensive. I've mostly used them to build
storage
> shelves out of 2x4's. They cost $6.50 for 100 2 1/2" screws at the
> local full service lumber yard (not at Lowes or Home Depot). The
> best thing about them is I don't have to drill *any* pilot holes in
> the top or bottom piece and yet they don't cause the wood to split,
> even if I am fastening close to the edge of the board. They save
me
> a lot of time on jobs where I used to drill pilot holes.
>
> I've not tried them on any boat projects. I'm not sure about the
> coating.
>
>
> --- Inbolger@yahoogroups.com, "Chuck Leinweber" <chuck@d...> wrote:
> > Hi, Lincoln:
> >
> > I base that opinion on my fairly limited experience and some
> observation.
> > When you use SD screws in metal, the shavings tend to fall out of
> the hole
> > because the flutes of the drill part of the screw are about a
> quarter inch
> > deep and the metal is normally half that or less. When you screw
> wood, it
> > is normally thicker than a quarter, and the shavings will end up
in
> the hole
> > with the screw threads and result in a weak hold. That said, if
> the screw
> > is to be temporary, it only needs to hold enough to get the job
> done, and
> > that may be enough.
> >
> > As I said, I have limited experience with using these screws in
> wood, and
> > have not done any tests, so I could be wrong. I base my opinion
on
> indirect
> > experience building various things with both wood and metal over
> the last
> > forty years.
> >
> > As far as leaving screws in the boat, I believe that more is
> better. Wood
> > has a tendency to split along the grain, and chine logs will split
> > lengthwise if given a reason to. In addition, Plywood will split
> within a
> > single layer. If you put a screw through ply into a chine log,
you
> > reinforce both the ply and the lumber perpendicular to the
grain.
> This can
> > only improve the ultimate strength of the boat.
> >
> > My $.02 worth.
> >
> > Chuck
> >
> >
> >
> > What's wrong with self drilling screws in wood? I"ve had good
> luck with
> > them, at least for clamping purposes. I tend not to leave too
> many
> > screws in the finished boat.
> >
> >
> >
> > [Non-text portions of this message have been removed]
Bruce,
Cool! I'm going to try these. Now if only they were available in
silicon bronze. Thanks for the link.
Chuck,
Ahhhh - so *thats* self-drilling. Now I get it.
Frank San Miguel
Wilmington, DE
--- Inbolger@yahoogroups.com, "Bruce Hector" <bruce_hector@h...>
wrote:
Cool! I'm going to try these. Now if only they were available in
silicon bronze. Thanks for the link.
Chuck,
Ahhhh - so *thats* self-drilling. Now I get it.
Frank San Miguel
Wilmington, DE
--- Inbolger@yahoogroups.com, "Bruce Hector" <bruce_hector@h...>
wrote:
> Here's a link to Lee Valley on line store where I buy my StainlessAnd
> Steel Interupted Thread screws, they only rarely split any stock.
> when they do, it's soft, dry pine at too thin a section. I likethem.
>and
>http://www.leevalley.com/hardware/page.asp?
> page=41314&category=3,41306&ccurrency=2&SID=
>
> Watch the word wrap. Which I just found out to mean: either copy
> paste the two halves into the address window before you hit "GO" ora
> to carefully hand type it all in. Works for me, a computer nimrod.
>
> Bruce Hector
> http:www.brucesboats.com
> We use the self drilling cadmium plated screws in the auto shop as
> quick way to attach two sheets of sheet metal or to re-attach thinline
> stamping brackets. Also great for mounting mudflaps, no need to
> up two different holes, just drill through the flap and into theor
> fender lip. Clamped in a drill chuck they'll even cut through two
> three layers of sheet metal at angles approaching 45 degrees.They're
> only good for one try, as they dull quickly. If one doesn;t makethe
> cut, throw it away and get a new one.
Here's a link to Lee Valley on line store where I buy my Stainless
Steel Interupted Thread screws, they only rarely split any stock. And
when they do, it's soft, dry pine at too thin a section. I like them.
http://www.leevalley.com/hardware/page.asp?
page=41314&category=3,41306&ccurrency=2&SID=
Watch the word wrap. Which I just found out to mean: either copy and
paste the two halves into the address window before you hit "GO" or
to carefully hand type it all in. Works for me, a computer nimrod.
Bruce Hector
http:www.brucesboats.com
We use the self drilling cadmium plated screws in the auto shop as a
quick way to attach two sheets of sheet metal or to re-attach thin
stamping brackets. Also great for mounting mudflaps, no need to line
up two different holes, just drill through the flap and into the
fender lip. Clamped in a drill chuck they'll even cut through two or
three layers of sheet metal at angles approaching 45 degrees. They're
only good for one try, as they dull quickly. If one doesn;t make the
cut, throw it away and get a new one.
Steel Interupted Thread screws, they only rarely split any stock. And
when they do, it's soft, dry pine at too thin a section. I like them.
http://www.leevalley.com/hardware/page.asp?
page=41314&category=3,41306&ccurrency=2&SID=
Watch the word wrap. Which I just found out to mean: either copy and
paste the two halves into the address window before you hit "GO" or
to carefully hand type it all in. Works for me, a computer nimrod.
Bruce Hector
http:www.brucesboats.com
We use the self drilling cadmium plated screws in the auto shop as a
quick way to attach two sheets of sheet metal or to re-attach thin
stamping brackets. Also great for mounting mudflaps, no need to line
up two different holes, just drill through the flap and into the
fender lip. Clamped in a drill chuck they'll even cut through two or
three layers of sheet metal at angles approaching 45 degrees. They're
only good for one try, as they dull quickly. If one doesn;t make the
cut, throw it away and get a new one.
Before we continue this discussion, I should point out that there are different definitions of "self drilling". My understanding of the term is that each screw has an actual drill bit on the end of the shank, such as is used to attach siding to metal buildings. These are not suitable for boats:
http://www.allproducts.com/search/products/pM01030134.shtml
Apparently, though, there are some screws that are called self drilling but which are much different, and could be used quite well for boats:
http://www.screw-products.com/gold.htm
These do not have a drill bit on the end, but are 'cut' in such a way that they do drill their own pilot, and more importantly, they are meant for wood. My comments on "self drilling" screws were based on the first example, and if you google "self drilling screws" they are what you see. But as is common in this type of conversation, we were not all on the same page. Hopefully this will clear things up a bit.
To make things worse, there are also "self tapping" screws which look similar to the second example above, but are meant for metal.
Chuck
http://www.allproducts.com/search/products/pM01030134.shtml
Apparently, though, there are some screws that are called self drilling but which are much different, and could be used quite well for boats:
http://www.screw-products.com/gold.htm
These do not have a drill bit on the end, but are 'cut' in such a way that they do drill their own pilot, and more importantly, they are meant for wood. My comments on "self drilling" screws were based on the first example, and if you google "self drilling screws" they are what you see. But as is common in this type of conversation, we were not all on the same page. Hopefully this will clear things up a bit.
To make things worse, there are also "self tapping" screws which look similar to the second example above, but are meant for metal.
Chuck
----- Original Message -----
From: sanmi
To:bolger@yahoogroups.com
Sent: Wednesday, June 18, 2003 7:29 AM
Subject: [bolger] Re: Self tapping vs. wood screws
I've been using some swiss cabinet screws around the house that are
self drilling and made for wood. Look kind of like drywall screws
but are much more expensive. I've mostly used them to build storage
shelves out of 2x4's. They cost $6.50 for 100 2 1/2" screws at the
local full service lumber yard (not at Lowes or Home Depot). The
best thing about them is I don't have to drill *any* pilot holes in
the top or bottom piece and yet they don't cause the wood to split,
even if I am fastening close to the edge of the board. They save me
a lot of time on jobs where I used to drill pilot holes.
I've not tried them on any boat projects. I'm not sure about the
coating.
--- Inbolger@yahoogroups.com, "Chuck Leinweber" <chuck@d...> wrote:
> Hi, Lincoln:
>
> I base that opinion on my fairly limited experience and some
observation.
> When you use SD screws in metal, the shavings tend to fall out of
the hole
> because the flutes of the drill part of the screw are about a
quarter inch
> deep and the metal is normally half that or less. When you screw
wood, it
> is normally thicker than a quarter, and the shavings will end up in
the hole
> with the screw threads and result in a weak hold. That said, if
the screw
> is to be temporary, it only needs to hold enough to get the job
done, and
> that may be enough.
>
> As I said, I have limited experience with using these screws in
wood, and
> have not done any tests, so I could be wrong. I base my opinion on
indirect
> experience building various things with both wood and metal over
the last
> forty years.
>
> As far as leaving screws in the boat, I believe that more is
better. Wood
> has a tendency to split along the grain, and chine logs will split
> lengthwise if given a reason to. In addition, Plywood will split
within a
> single layer. If you put a screw through ply into a chine log, you
> reinforce both the ply and the lumber perpendicular to the grain.
This can
> only improve the ultimate strength of the boat.
>
> My $.02 worth.
>
> Chuck
>
>
>
> What's wrong with self drilling screws in wood? I"ve had good
luck with
> them, at least for clamping purposes. I tend not to leave too
many
> screws in the finished boat.
>
>
>
> [Non-text portions of this message have been removed]
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[Non-text portions of this message have been removed]
I've been using some swiss cabinet screws around the house that are
self drilling and made for wood. Look kind of like drywall screws
but are much more expensive. I've mostly used them to build storage
shelves out of 2x4's. They cost $6.50 for 100 2 1/2" screws at the
local full service lumber yard (not at Lowes or Home Depot). The
best thing about them is I don't have to drill *any* pilot holes in
the top or bottom piece and yet they don't cause the wood to split,
even if I am fastening close to the edge of the board. They save me
a lot of time on jobs where I used to drill pilot holes.
I've not tried them on any boat projects. I'm not sure about the
coating.
self drilling and made for wood. Look kind of like drywall screws
but are much more expensive. I've mostly used them to build storage
shelves out of 2x4's. They cost $6.50 for 100 2 1/2" screws at the
local full service lumber yard (not at Lowes or Home Depot). The
best thing about them is I don't have to drill *any* pilot holes in
the top or bottom piece and yet they don't cause the wood to split,
even if I am fastening close to the edge of the board. They save me
a lot of time on jobs where I used to drill pilot holes.
I've not tried them on any boat projects. I'm not sure about the
coating.
--- Inbolger@yahoogroups.com, "Chuck Leinweber" <chuck@d...> wrote:
> Hi, Lincoln:
>
> I base that opinion on my fairly limited experience and some
observation.
> When you use SD screws in metal, the shavings tend to fall out of
the hole
> because the flutes of the drill part of the screw are about a
quarter inch
> deep and the metal is normally half that or less. When you screw
wood, it
> is normally thicker than a quarter, and the shavings will end up in
the hole
> with the screw threads and result in a weak hold. That said, if
the screw
> is to be temporary, it only needs to hold enough to get the job
done, and
> that may be enough.
>
> As I said, I have limited experience with using these screws in
wood, and
> have not done any tests, so I could be wrong. I base my opinion on
indirect
> experience building various things with both wood and metal over
the last
> forty years.
>
> As far as leaving screws in the boat, I believe that more is
better. Wood
> has a tendency to split along the grain, and chine logs will split
> lengthwise if given a reason to. In addition, Plywood will split
within a
> single layer. If you put a screw through ply into a chine log, you
> reinforce both the ply and the lumber perpendicular to the grain.
This can
> only improve the ultimate strength of the boat.
>
> My $.02 worth.
>
> Chuck
>
>
>
> What's wrong with self drilling screws in wood? I"ve had good
luck with
> them, at least for clamping purposes. I tend not to leave too
many
> screws in the finished boat.
>
>
>
> [Non-text portions of this message have been removed]
Hi, Lincoln:
I base that opinion on my fairly limited experience and some observation.
When you use SD screws in metal, the shavings tend to fall out of the hole
because the flutes of the drill part of the screw are about a quarter inch
deep and the metal is normally half that or less. When you screw wood, it
is normally thicker than a quarter, and the shavings will end up in the hole
with the screw threads and result in a weak hold. That said, if the screw
is to be temporary, it only needs to hold enough to get the job done, and
that may be enough.
As I said, I have limited experience with using these screws in wood, and
have not done any tests, so I could be wrong. I base my opinion on indirect
experience building various things with both wood and metal over the last
forty years.
As far as leaving screws in the boat, I believe that more is better. Wood
has a tendency to split along the grain, and chine logs will split
lengthwise if given a reason to. In addition, Plywood will split within a
single layer. If you put a screw through ply into a chine log, you
reinforce both the ply and the lumber perpendicular to the grain. This can
only improve the ultimate strength of the boat.
My $.02 worth.
Chuck
What's wrong with self drilling screws in wood? I"ve had good luck with
them, at least for clamping purposes. I tend not to leave too many
screws in the finished boat.
[Non-text portions of this message have been removed]
I base that opinion on my fairly limited experience and some observation.
When you use SD screws in metal, the shavings tend to fall out of the hole
because the flutes of the drill part of the screw are about a quarter inch
deep and the metal is normally half that or less. When you screw wood, it
is normally thicker than a quarter, and the shavings will end up in the hole
with the screw threads and result in a weak hold. That said, if the screw
is to be temporary, it only needs to hold enough to get the job done, and
that may be enough.
As I said, I have limited experience with using these screws in wood, and
have not done any tests, so I could be wrong. I base my opinion on indirect
experience building various things with both wood and metal over the last
forty years.
As far as leaving screws in the boat, I believe that more is better. Wood
has a tendency to split along the grain, and chine logs will split
lengthwise if given a reason to. In addition, Plywood will split within a
single layer. If you put a screw through ply into a chine log, you
reinforce both the ply and the lumber perpendicular to the grain. This can
only improve the ultimate strength of the boat.
My $.02 worth.
Chuck
What's wrong with self drilling screws in wood? I"ve had good luck with
them, at least for clamping purposes. I tend not to leave too many
screws in the finished boat.
[Non-text portions of this message have been removed]
As a practical matter, teh greatest difference between wood and
sheetmetal screws is that the wood screw has an unthreaded shank.
To use a metal screw to hold two pieces of wood together, you need
to drill an oversized hole in the top piece to allow the screw to
draw the joint tight. Screws hold better when a pilot hole has been
drilled and this should except for temporary or quick & dirty work.
To keep from needing such a large inventory, I always use the sheet
metal screws and tolerate having to drill the top clearance hole
when necessary.
sheetmetal screws is that the wood screw has an unthreaded shank.
To use a metal screw to hold two pieces of wood together, you need
to drill an oversized hole in the top piece to allow the screw to
draw the joint tight. Screws hold better when a pilot hole has been
drilled and this should except for temporary or quick & dirty work.
To keep from needing such a large inventory, I always use the sheet
metal screws and tolerate having to drill the top clearance hole
when necessary.
--- Inbolger@yahoogroups.com, "Ed Williams" <ed_laurine@j...> wrote:
pronounced thread and a self tapping screw,used for sheet metal,has a
finer and shallower thread.The big"disadvantage" to using a self
tapping screw in wood is that you may quickly and too easily strip
the hole(since there will be less thread into the wood)thereby losing
the ability to tighten down on the screw and draw the plywood snuggly
against the ribs.
Sincerely,
Peter Lenihan,number one fan of Robertson drive SS wood screws,from
along the rain soaked shores of the St.Lawrence.........
> To All:Based on what I have observed,a true wood srew has a deeper,more
>
> To attach the hull plywood to the ribs, what are the advantages and
> disadvantages of SS self tapping vs. SS wood screws?
>
> Ed Williams
pronounced thread and a self tapping screw,used for sheet metal,has a
finer and shallower thread.The big"disadvantage" to using a self
tapping screw in wood is that you may quickly and too easily strip
the hole(since there will be less thread into the wood)thereby losing
the ability to tighten down on the screw and draw the plywood snuggly
against the ribs.
Sincerely,
Peter Lenihan,number one fan of Robertson drive SS wood screws,from
along the rain soaked shores of the St.Lawrence.........
Wood screws are by definition "self tapping". Their are also "self drilling" screws which should not be used with wood, except to attach wood to a metal substrate.
Chuck
Chuck
----- Original Message -----
From: Richard Spelling
To:bolger@yahoogroups.com
Sent: Friday, June 13, 2003 12:18 PM
Subject: Re: [bolger] Self tapping vs. wood screws
To the ribs in what? Metal ribs? Oak ribs? Pine ribs? BBQ ribs?
Aren't self tapping screws designed for metal?
----- Original Message -----
From: "Ed Williams" <ed_laurine@...>
To: <bolger@yahoogroups.com>
Sent: Friday, June 13, 2003 12:12 PM
Subject: [bolger] Self tapping vs. wood screws
> To All:
>
> To attach the hull plywood to the ribs, what are the advantages and
> disadvantages of SS self tapping vs. SS wood screws?
>
> Ed Williams
>
>
>
> Bolger rules!!!
> - no cursing, flaming, trolling, spamming, or flogging dead horses
> - stay on topic, stay on thread, punctuate, no 'Ed, thanks, Fred' posts
> - add your comments at the TOP and SIGN your posts and <snip> away
> - To order plans: Mr. Philip C. Bolger, P.O. Box 1209, Gloucester, MA, 01930, Fax: (978) 282-1349
> - Unsubscribe:bolger-unsubscribe@yahoogroups.com
> - Open discussion:bolger_coffee_lounge-subscribe@yahoogroups.com
>
> Your use of Yahoo! Groups is subject tohttp://docs.yahoo.com/info/terms/
>
>
Yahoo! Groups Sponsor
Bolger rules!!!
- no cursing, flaming, trolling, spamming, or flogging dead horses
- stay on topic, stay on thread, punctuate, no 'Ed, thanks, Fred' posts
- add your comments at the TOP and SIGN your posts and <snip> away
- To order plans: Mr. Philip C. Bolger, P.O. Box 1209, Gloucester, MA, 01930, Fax: (978) 282-1349
- Unsubscribe:bolger-unsubscribe@yahoogroups.com
- Open discussion:bolger_coffee_lounge-subscribe@yahoogroups.com
Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.
[Non-text portions of this message have been removed]
To the ribs in what? Metal ribs? Oak ribs? Pine ribs? BBQ ribs?
Aren't self tapping screws designed for metal?
Aren't self tapping screws designed for metal?
----- Original Message -----
From: "Ed Williams" <ed_laurine@...>
To: <bolger@yahoogroups.com>
Sent: Friday, June 13, 2003 12:12 PM
Subject: [bolger] Self tapping vs. wood screws
> To All:
>
> To attach the hull plywood to the ribs, what are the advantages and
> disadvantages of SS self tapping vs. SS wood screws?
>
> Ed Williams
>
>
>
> Bolger rules!!!
> - no cursing, flaming, trolling, spamming, or flogging dead horses
> - stay on topic, stay on thread, punctuate, no 'Ed, thanks, Fred' posts
> - add your comments at the TOP and SIGN your posts and <snip> away
> - To order plans: Mr. Philip C. Bolger, P.O. Box 1209, Gloucester, MA, 01930, Fax: (978) 282-1349
> - Unsubscribe:bolger-unsubscribe@yahoogroups.com
> - Open discussion:bolger_coffee_lounge-subscribe@yahoogroups.com
>
> Your use of Yahoo! Groups is subject tohttp://docs.yahoo.com/info/terms/
>
>
To All:
To attach the hull plywood to the ribs, what are the advantages and
disadvantages of SS self tapping vs. SS wood screws?
Ed Williams
To attach the hull plywood to the ribs, what are the advantages and
disadvantages of SS self tapping vs. SS wood screws?
Ed Williams