Galvanized CT wood screws

I am getting ready to have my old wooden mission boat refastened and am looking for a source for around 3,000 #18 x 2 1/2" cut thread flat head slotted hot-dip galvanized wood screws (wow, that's a mouthfull). I thought that this would not be that difficult a task, but silly me. None to be found. I am ready to by non-galvanized or zinc plated and have them galvanized at our local galvanizer. Can anyone suggest a source for quality screws of this nature, either galvanized or not? Thanks in advance for any guidance.

 

well there is http://www.oemfasteners.net/ and luke bronco started a thread about ti cut thread woodscrews, however they have bronze in stock already...i dont know about galvinised.

 

oemfasteners.com

Redsky, thanks for the lead, but I have tried them already. Charlie there went the extra mile to find galvanized for me, but without luck. I may try them again for plain steel, if I have to go that route.

 

How about stainless screws ?:
http://www.stainless-fasteners.com/Sharx.htm

 

Deeman, thanks for the lead, but I need to stick with galvanized. The 50-year old fasteners now in the planking are/were galvanized boat nails. We won't be pulling them during refastening, so I need to stick with as similar a metal as possible.

 

All the hot dipped 'screws' I've seen, (I've only seen lag bolts) are crude affairs, where the galvanising tends to fill in the screw threads with lumps to the point where in the smaller sizes (1/4") it seems they are more like a ring shank nail than a screw. I would think the lumps would ream out the pilot hole and effect the holding power a bunch. I would also think the galv. would fill in the screwdriver slot and that seems like it might be a major reason why they don't make them. Can't you use silicon bronze screws? Sam

 

Sam2 -- Tks for the comments and suggestions. Since the old fastenings (galvanized boat nails of 50 years ago) have deteriorated to the point that we cannot extract them, we will be refastening in new holes in close proximity. Using silicon bronze would add too many dissimilar metals to the soup.

 

hmmmm here is a possable suggestion depending on how you deel about them iv used these things to mount all kinds of heavy objects to 2x4's with far more hoding power and sucess than anything else in 15 years associating with construction stuff....drywall screws...iv not found them to need a pilot hole...their thread gap is about double a normal woodscrews...it might be pissable to get these in galvinized already or have a bunch dipped aound this area ...if you dont mind phillips head....

 

the only problem with sheetrock type screws (or "decking" screws, in the case of HDG) is that in a 2 1/2" length, you're only going to find a #8 or MAYBE (if you're lucky) a #10

Unless the original post was a typo, he's looking for a #18... which would be somewhere around 5/16" thick

Mission... check with Fastenal... they have the SIZE you're looking for here:
http://www.fastenal.com/web/products/detail.ex?sku=30293
but the description says zinc plated, not HDG

maybe give them a call or e-mail and see if they're available on a spec order basis.

good luck

 

I understand about dissimilar metals and corrosion. Can someone tell me though whether this is really a concern on a wood boat given that the screws won't be coming into contact with each other?

Is the problem that the wood has enough moisture contact to conduct electrons? Is that the problem?

When I was building some patio furniture, I found some epoxy-coated screws. It was an interesting idea, I thought, but I don't know how well they would work at preventing corrosion. My gut instinct tells me you'd still get corrosion in whatever places the epoxy coating chips or gets nicked. Is that correct?

Finally, why can't you take some "easy outs" (I know I know, they're not easy at all...) and drill out the fasteners? Seems that would be the best way to do it. And that way, you could use whatever types of nails you wanted. I can imagine the electrolytic action corroding metal screws within a half an inch or an inch of each other... but beyond that it doesn't seem likely. Can anybody comment on this?


[sorry for the threadjack. Arrrr! I'm a pirate of the internets!]

 

The guy who restores my stuff says it is universally accepted among the restorers he knows, to get the iron fasteners out of old wooden boats. He lists this as the biggest problem found, usually. He calls it iron sickness and it affects the wood, not just a rotten fastener and its hole. He is also animated about not mixing fastener material types, ever.

I went through this same discussion when doing my 1960 Chris Craft, thinking I could save some money with stainless (which he thinks even less of then galvanized) or maybe some galvanized fasteners. He indicated stainless is useless if placed under water or in wet wood, rusting almost as fast as a bright finished common nail. He laughed hard at the idea of drywall screws and showed me how truly weak, easily broken and quick to rust they are. He uses them in jigs and temporary setups and they clearly do not last very long exposed to weather, let alone in harsher marine life.

A fastener used under the waterline, will be in direct contact with the other fasteners, by way of the water and this is what causes dissimilar metals to corrode. He said it makes the boat a battery, the water is the electrolyte and the fasteners are anodes or cathodes depending on what they are made of, if I remember the conversations correctly. So a bronze fastener, placed several feet from a steel one will still suffer the same corrosion, if in contact with wet wood or under the water.

In the end the comment, you have to use bronze with bronze, galvanized with galvanized or replace the galvanized completely with bronze, is what I remember most. I saw several examples of removed, dead screws and pieces of wood that had been replaced, where the old galvanized screws or nails had wasted away. Bronze fasteners that had become dust in their holes or severely weakened wood in the area of a rusted old galvanized fastener, unable to accept a replacement screw or nail from the damage to the wood. I also saw 45 year old bronze screws removed from my boat that looked pretty good after years on a mooring and was grateful Chris Craft choose to use this material, instead of galvanized.

Sorry about the long post.

 

it was a thought to have the drywall screws of the proper length galvinised, im just not that fond of normal woodscre thread pattern..
i think there is a torx head deck screw that they use for artifical decking now that comes in that thicker size ...

 

A proper boat wood screw is quite different then the average screw. All wood screws are now a rolled thread. A real boat screw is a cut thread screw which has a shank diameter the same as the thread, meaning it will permit the wet wood to swell tight against it, sealing the hole, if properly installed. A rolled thread screw requires a larger clearance hole, because the threads stand proud of the shank, which is to big for normal swelling to seal the hole.

Drywall screws are dainty shank things that haven't any business on a boat. The bugle head doesn't seal well and I have never seen a proper shaped counter sink that will permit them to seal. The bugle head was designed to squish the paper in drywall without tearing it. A real counter sink head provides the most pressure a screw can provide. I'm not sure what you do not like about the normal wood screw thread pattern, but they have much better holding power then the very aggressive drywall screw style thread.

The black phosphorus or coated mild steel used in deck and drywall screws will not survive long in marine life. Galvanizing a weak fastener, just does not make much sense to me.

I replaced several thousand screws on the planking of my Chris and the price at times ticked me off, but they are equal or better in quality then the nearly 50 year old ones they replaced. Is this an area you think wise to economize? Log onto www.mcfeelys.com and have a look at some real boat wood screws. They come in square drive, plus the other drive styles too. More importantly you will see the difference between a cut screw and a rolled screw, which can make a huge difference in sealing up an old wooden boat.

 

no i wasent really looking to economise with bad fasteners. iv always had problems with reg pattern woodscrews splitting wood..stripping the drive threads before seat is made and or haveing the reg woodscrew pattern strip the hole just before seating or just after..iv used pilot holes soap on the threads and just about every other trick iv heard of, so i find them frustrating and i dont like working with them.

 

You may not find them. I have a different problem but the same need for HDGs.
Glen-L has "some" but not a big selection as they are discontinueing stocking them. Call, ...they are not in the catalog any longer.
New cheaper processes & new EPA restrictions are killing the HDG industrys. I was told the very process leaves clumps of zink in the slots & the "redo rate" is very high. For this reason alone they are turning to other coatings.
After DAYS of searches, this is as close as I've come.
http://www.highlandwoodworking.com/index.asp?PageAction=VIEWCATS&Category=412