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#272751 - 05/24/14 09:03 PM beams  
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mousetrap Offline
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Warners bay , nsw , Australia
Is there a specific grade of aluminium for the beams?


Cheers,Dave.
CHA-CHING 922
BITE ME 1749
-- Have You Seen This? --
#272757 - 05/25/14 02:19 AM Re: beams [Re: mousetrap]  
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Gippsland Lakes Victoria Aust...
Hi Dave,

Nothing in the building restrictions that I can see regarding grade of alloy. The following is the only applicable part I can see that effects beam materials.

"The main beam and rear beam shall each be of straight aluminium alloy of constant section along its length. Holes may be drilled in the beams for fastenings only. Holes remaining after the removal of redundant fittings are permitted.
6.2
The main and rear beam shall be; a rectangular hollow section 50 mm plus or minus 1 mm by 39 mm plus or minus 1 mm by minimum 3 mm wall. Beam edges may be rounded to a maximum of 2 mm radius."

From my experience this size only leaves Mossies with a choice of a standard section from Capral, available at most alloy fabricators/sellers around the country. Though it does come in a choice? of internal corners rounded or not, rounded internal corners is preferrable, in particular if you are not bolting beams right through.

Have you found a alternative in this size?



Regards Gary.
Mosquito 1830
All opions expressed in this post are mine and mine alone, no assumptions should be made regarding any Associations or Clubs I may be a member of.
#272760 - 05/25/14 06:00 AM Re: beams [Re: mousetrap]  
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I have just bought beams for myself from capral and cost $72 for a 6.5M lenght 50.8 x 39.2 x 3mm untreated and pick up. it has internal radius.

Matt

Last edited by Matt_Stone; 05/25/14 06:01 AM.
#272763 - 05/25/14 06:12 AM Re: beams [Re: Matt_Stone]  
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Good price Matt, I expected it to be more than that for a full length shocked

Does the association carry the beams ?
(Reason I ask is I need 2new beams for 1740 and I also want a new mast aswell, killing two birds here wink )


Yar, & this ere post be done without a sin'le drop o' rum passin' me lips

Kingy
started with Impara Cadet #3 / Mosquito #245
& now Mosquitos #1182 & #1740

#272764 - 05/25/14 06:39 AM Re: beams [Re: mousetrap]  
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Mast batch should of been ordered (ill follow it up)
Yes the assoc do stock beams (i dont think we have any in stock. If not will be ordered with masts)

Matt

#272768 - 05/25/14 09:03 AM Re: beams [Re: Matt_Stone]  
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mousetrap Offline
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Was not sure if there were different grades of alloy as there is with stainless steel. Good tip on the internal round, I would not have thought of that. At that price I will be re-beaming next weekend. Thanks for the replies.


Cheers,Dave.
CHA-CHING 922
BITE ME 1749
#272785 - 05/26/14 01:36 AM Re: beams [Re: mousetrap]  
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Gippsland Lakes Victoria Aust...
Hi Dave,

What boat are you re beaming? I thought we did all 3 Mossies I got from Port Lincoln 1747,1749 & 1760, remember buying a number of lengths of beam section from local alloy supplier, even had some left over, in fact sold the last left over beam to Matt a while back.


Regards Gary.
Mosquito 1830
All opions expressed in this post are mine and mine alone, no assumptions should be made regarding any Associations or Clubs I may be a member of.
#272833 - 05/28/14 07:01 AM Re: beams [Re: stillbitten]  
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Hi Gary
Re-beaming 1749 "BITE ME". Found a small hairline crack 5mm inboard side of where the tie bolts to the main beam. Small amount of corrosion looks like the cause.


Cheers,Dave.
CHA-CHING 922
BITE ME 1749
#272863 - 05/29/14 01:37 AM Re: beams [Re: mousetrap]  
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Gippsland Lakes Victoria Aust...
The joy of getting older can't remember stuff blush , obviously didn't re beam 1749 frown


Regards Gary.
Mosquito 1830
All opions expressed in this post are mine and mine alone, no assumptions should be made regarding any Associations or Clubs I may be a member of.
#272865 - 05/29/14 05:20 AM Re: beams [Re: mousetrap]  
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hmmm thats where daniels cracked too, put a 20x40x3mm plate/ washer on the strap when bolting on to the beam.

Matt

#273442 - 06/24/14 11:49 PM Re: beams [Re: Matt_Stone]  
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Originally Posted by Matt_Stone
hmmm thats where daniels cracked too, put a 20x40x3mm plate/ washer on the strap when bolting on to the cross beam .

Matt


Agree with the mate about aluminium cross beams .

Last edited by aparkfind; 06/24/14 11:50 PM.
#273695 - 07/04/14 01:10 AM Re: beams [Re: aparkfind]  
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Just out of interest in regard to the mast sections from the association, are they anodised? or natural?

Cheers


Taipan AUS329 'Got Wood'
Mosquito 752 'Sticky Finger'
HARDWOOD RACING TEAM
#273711 - 07/04/14 04:36 PM Re: beams [Re: mousetrap]  
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anodised

#274063 - 07/21/14 06:53 PM Re: beams [Re: Matt_Stone]  
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Hey Matt,

I'm in the process of replacing the rear beam on 1747. (PS. for Gary: 1747 rear beam was definitely not replaced!)

Does the Capral section you bought have an external radius too? I've got Nic's boat at my place and his seems to have a small radius on the outer edges also which is a nice detail. ( I think PhilWS beamed his so I would assume the assoc supplied these?)

Is there assoc. stock available and are they anodized? Either way I need to get some beams over the next few weeks.

Cheers
Doug

Attached Files
beam.JPG (166 downloads)
#274067 - 07/22/14 03:37 AM Re: beams [Re: SFJF 1747]  
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Hi Doug,

No need to rub it in, I thought we had established the fact I don't have a memory cry.

The Capral section doesn't have a radius on outside corners. Phil WS does this himself before he gets them anodised, to supply on the boats he sells (which are not sold by the association).

On the beams I did replace, 1760 and confused. I did the radius myself, it's not that difficult, I did a lot of it with sandpaper, before anodising. Getting them anodised is not difficult in the Eastern Suburbs (mine where done around Cheltenham Road I think?) as long as you are not in a rush and can wait till they have enough for a bath lot.

Contact Phillip WS direct to check if VMCA has any beams For Sale and if they are anodised.


Regards Gary.
Mosquito 1830
All opions expressed in this post are mine and mine alone, no assumptions should be made regarding any Associations or Clubs I may be a member of.
#274087 - 07/22/14 04:42 PM Re: beams [Re: mousetrap]  
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Hi Doug, as Gary said, I do also radius the edge with a fine flapper disc on grinder then go with the grain with scotch brute pad to clean all grease and make it smooth ready for anodizing, I do have a section at home I could sell you a beam or make one up for u
Matt

#274088 - 07/22/14 04:43 PM Re: beams [Re: mousetrap]  
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Also I can get it anodized for you about$60

#274089 - 07/22/14 05:15 PM Re: beams [Re: mousetrap]  
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Thanks gents grin

#274093 - 07/22/14 09:54 PM Re: beams [Re: mousetrap]  
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2 questions .....

1/
Is it within the rules to "radius" the beams ?
I know there's a limit on the deck/hull radius, so logic would suggest ...


2/
Wouldn't it be best to actually fit the beams to the boat and also the associated hardware (IE: trampoline, traveler bar, dolphin striker etc etc)
And then strip it all off and THEN get it anadosied ????

Cant see the sense in drilling holes and exposing raw alloy after the anadosing

Reason I ask is.....
1182 has an anodised rear beam and a 'painted' front beam, the rear looks a treat until you remove a component (in my case the traveler bar), the corrosion around the holes that were obviously drilled post anodising is a concern, and yet the corrosion on the pained front beam is probably less in comparision
(more on this comming to Shy's thread soon).......

wink



Last edited by PIRATE; 07/22/14 10:00 PM. Reason: Cause the "smart-phone" aint !!!

Yar, & this ere post be done without a sin'le drop o' rum passin' me lips

Kingy
started with Impara Cadet #3 / Mosquito #245
& now Mosquitos #1182 & #1740

#274105 - 07/23/14 03:55 PM Re: beams [Re: mousetrap]  
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To windward of you!
Yes there is a rule on radius of the beams. Rule 6.2.
I would suggest it is a good idea for everyone to read through the rules at some stage. If you read the rules and check your own boat it saves the embarrasment when it doesnt measure at a regatta.

http://www.theracingcat.com/uploads/Mosquito_BRR.pdf


"Sixth Element"
1782 MK2 w/spinnaker.
Lake Bonney Y.C.
National Sec. / S.A President / S.A Measurer / Commodore LBYC
#274107 - 07/23/14 04:30 PM Re: beams [Re: mousetrap]  
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OK peoples, max radius is 2 to 3 mm and yes fit the beam out and trial fit it then strip it down then get it anodized. When you have an existing beam to copy off, no need to trial fit,

Matt

#274110 - 07/23/14 05:21 PM Re: beams [Re: mousetrap]  
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Make sure you measure the boat for maximum width before drilling holes. Don't drill any holes in the beam until you check out the hull where it will be mounted, you may prefer to plug the holes and put bolts in a new area


Jeff Southall
Nacra 5.8 1667 Ram Raider
Nacra 18 Square
Taipan 5.7 134
Mosquito 404
Arrow 1576
#274126 - 07/24/14 05:07 AM Re: beams [Re: Matt_Stone]  
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Pirate Offline
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seeing I'm going to replace both the beams on Karp I may as well 'radius' the beams while I'm at it.....
YAY .... no more scun skin mad

How would a router go at making the radius edge over a flapper disc I have heaps of bits that would make a very nice curve and several that I'm not fussed in loosing ...

Other than that does it have to be a curve, could I for example simply bevel the edge with a plane ???



Yar, & this ere post be done without a sin'le drop o' rum passin' me lips

Kingy
started with Impara Cadet #3 / Mosquito #245
& now Mosquitos #1182 & #1740

#274129 - 07/24/14 05:36 AM Re: beams [Re: mousetrap]  
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To support Peterís suggestion and with no malice directed to Matt, if you decide to remove the corner/arris of the beams, BRR states a maximum radius of 2mm. BRR 6.2 The main and rear beam shall be; a rectangular hollow section 50 mm plus or minus 1 mm by 39 mm plus or minus 1 mm by minimum 3 mm wall. Beam edges may be rounded to a maximum of 2 mm radius. From the Building Instructions: A 2mm radius arris can be removed from the cross beams. This is a restricted measurement! Make a radius guide by drilling a 4mm hole through a piece of sheetmetal. Remove the corner along the tangent lines. See Diag. 8.2. Remove the beam arris. Plane off the bulk with a woodwork hand plane, a No.4 or No.5 is ideal. Draw file with a mill 2nd cut file to final shape. Smooth with emery cloth.
I have heard of using a router with a radius cutter. This would also work but ensure the correct size cutter is selected and it is tungsten tipped as a HSS will dull before completion. Removing too much material from the corners will compromise the strength of the beam and it is a fact that mozzie beams are notoriously under engineered.
[Linked Image]


Tortured ply is clearly beautiful.
Mozzie Aldebaran VI
1827
#274130 - 07/24/14 05:51 AM Re: beams [Re: mousetrap]  
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I find this all very interesting but I am moved to ask, why put an external radius on the beams? Is it for appearance, comfort of the sailor(s) or weight reduction?


1140 Gadfly
1434 J.I.B.E.
1727 Atreus
#274156 - 07/24/14 04:06 PM Re: beams [Re: mousetrap]  
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To windward of you!
hi Greg,

The main reason is for the comfort of the sailor. The new beams have a sharp square edge and they can cut if you slide into them etc.


"Sixth Element"
1782 MK2 w/spinnaker.
Lake Bonney Y.C.
National Sec. / S.A President / S.A Measurer / Commodore LBYC
#274159 - 07/24/14 04:47 PM Re: beams [Re: mousetrap]  
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Yes that's right, I have cut myself lots on sharp beams

#274163 - 07/24/14 07:10 PM Re: beams [Re: mousetrap]  
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I see. Thanks Peter and Matt.


1140 Gadfly
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1727 Atreus
#274167 - 07/24/14 09:04 PM Re: beams [Re: Sixth Element]  
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Whilst Karp's & Shy's front beams arent radiused I certainly intend to do the new beams on Karp prior to anodising, and Shy will get the router treatment after all the burrs have been sanded off

Shy's front beams edge is nasty, years & years of mast raising/lowering and other unknown gear being dragged over it have left a serated edge specifically around the mast base ......
The marks on the boom would suggest it was loosely tied there during transporting....

I think that the removal of the edge other for human skin would be to stop such flaring of the square edge......
I dont hold much hope but I'll try for a pic of the nasty edge on Shy.

Is there any advantage in cutting a radius on the rear beam ???
There's a great big traveler beam sitting on them !!!!!

wink


Yar, & this ere post be done without a sin'le drop o' rum passin' me lips

Kingy
started with Impara Cadet #3 / Mosquito #245
& now Mosquitos #1182 & #1740

#274169 - 07/24/14 11:47 PM Re: beams [Re: mousetrap]  
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When sloop the skipper sits on the rear beam and the crew is trapping with foot on rear beam.... Nasty when something goes wrong with sharp edges

#274872 - 08/20/14 07:33 PM Re: beams [Re: Matt_Stone]  
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So a quick update:

Got internal radius beam sections from Capral as per Matt's notes and used a Tungsten Carbide 2mm rad router bit on a hand router which worked a treat to produce a consistent 2mm external radius.

In disassembling the old front beam and jumper strap assembly I noticed a fair bit of corrosion on the dolphin striker tube module so will have to replace this also. It also didn't have a great amount of tension on it which is a bit of a concern which leads me to the question...

I am a little perplexed why Mozzie setups don't have any tension adjustment in the design of this part. On my previous cat (a Paper Tiger) it was essential to have a bit of pre-tension on the front beam assembly to ensure no sag of the beam when under full load, and when new it allowed the jumper strap to settle and then be rechecked/tensioned as required.

Is this something the Mozzie doesn't need or is not allowed in the plans? To me it would seem like a good idea with the high loads on the rig with spinakers/double traps etc??

I was thinking I might replace it with this type of assembly..
Dolphin Striker PT

Be interested in anyone's thoughts and latest setups.

Cheers
Doug

#274873 - 08/20/14 09:38 PM Re: beams [Re: SFJF 1747]  
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I've seen a few that have had a non-adjustable striker setup, they are however pre-loaded during the build..... these boats have been in the 1650 numbers and up

Both my mozzies do have an adjustable striker as does the plan set I have which specifies a 5/16th stainless bolt with locknut & adjuster nut being tig welded to the down tube under the mast step.

I recall breaking a bolt on my first mozzie (245) way back when....


Yar, & this ere post be done without a sin'le drop o' rum passin' me lips

Kingy
started with Impara Cadet #3 / Mosquito #245
& now Mosquitos #1182 & #1740

#274874 - 08/20/14 10:52 PM Re: beams [Re: mousetrap]  
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With the non adjustable they were preloaded but the strap was also riveted so the strap didn't slop around and elongate the bolt holes thereby undoing the pretension, if the rivets are snapped off more than likely there's not much pretension. Bit hard to check as you need to take the main beam off. Can be scary to see how much corrosion there is between the stainless strap and aluminium beam


Jeff Southall
Nacra 5.8 1667 Ram Raider
Nacra 18 Square
Taipan 5.7 134
Mosquito 404
Arrow 1576
#274876 - 08/21/14 12:43 AM Re: beams [Re: mousetrap]  
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I'm currently replacing the beams on my boat and when i put the striker back on i will be adding a tensioning device to it. There was little to no pretension on it b4 which is probably why my beam had cracked.
When rigged (i run a pretty tight rig) my front beam usually sagged up to 5mm and probably more whilst sailing.
Also where the strap bolts to the beam add a square/rectangular stainless washer that spans the width of your strap so the strap won't stretch and possibly break at the bolt.
i hope that answers your question Doug

#274906 - 08/21/14 11:57 PM Re: beams [Re: mousetrap]  
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The strap is pre tention but after a while the beams settle in and the strap stretches. With no load on mast step the beam should have 3mm rise tension so when boat is loaded up the beam should be 1mm rise or straight. im adding a tension device to mine tho. cos I can

Last edited by Matt_Stone; 08/21/14 11:59 PM.
#274907 - 08/22/14 03:54 AM Re: beams [Re: mousetrap]  
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Is 3mm enough? most cats i have worked with require 10mm. 3mm would be pretty easy to compress under sailing loads, especially sloop rigged.


C2 AUS 222 by Goodall design
"Darph Bobo"
#274921 - 08/22/14 04:36 PM Re: beams [Re: mousetrap]  
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i stand to be corrected, i looked on the plans and the building rules and says nothing about tension, so personaly i would tension the beam so when the rig tension is on it has a positive bend of 1mm

#274928 - 08/23/14 05:16 PM Re: beams [Re: SFJF 1747]  
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Originally Posted by SFJF 1747
..... I am a little perplexed why Mozzie setups don't have any tension adjustment in the design of this part .....



does this help ?????


Scorpian's setup.....

[Linked Image]

TwiceShy's setup.....

[Linked Image]


Yar, & this ere post be done without a sin'le drop o' rum passin' me lips

Kingy
started with Impara Cadet #3 / Mosquito #245
& now Mosquitos #1182 & #1740

#274929 - 08/23/14 05:35 PM Re: beams [Re: Matt_Stone]  
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Originally Posted by Matt_Stone
i stand to be corrected, i looked on the plans and the building rules and says nothing about tension, so personaly i would tension the beam so when the rig tension is on it has a positive bend of 1mm


old trick from former state tittle holders....



hang the boat from a solid beam / rafter etc so that only the transom is resting on the ground

that hanging point is the centre tube / front beam connection point, use the TUBE and NOT the beam as the tie point


adjust the striker tension until it is FIRM but not overly tight..... lockup the locking nut .... done smile



This is a BASELINE set point....
a starting point for the fine tuners to play from, add slightly more tension for heavier weather and slightly less tension for light weather sailors. The amount you'd adjust would be (pending on the thread's per inch of the adjuster bolt) would be at most 3/4 of a turn, fine threaded bolts would obviously require more.

Final check is to rig the boat fully and reef in the main (and jib if fitted) to a high pointing position, sighting along the beam the beam should be dead straight .... if its not you need to make further adjustments.

wink


Yar, & this ere post be done without a sin'le drop o' rum passin' me lips

Kingy
started with Impara Cadet #3 / Mosquito #245
& now Mosquitos #1182 & #1740

#274936 - 08/24/14 02:10 AM Re: beams [Re: mousetrap]  
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In the photos you have there, those bolts are a little small and have known to fail, I'm putting in a 1\2 inch Unc thread as the striker post has to 19mm, so I will lathe up a nylon bush to keep the adjuster center of the 19mm tube

Last edited by Matt_Stone; 08/24/14 02:15 AM.
#275804 - 10/13/14 05:29 AM Re: beams [Re: mousetrap]  
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Port Vincent, SA
Hi all,

I will be doing a fairly urgent re-beam on the front of #1769 in the next week, due to a crack through both sides at the dolphin striker strap bolt. Following the advice of several experienced campaigners at the Meningie Nats, I added more tension to my beam by using washers as spacers between the mast post and strap. I think a tensioning bolt would be essential, and I'll try to incorporate one into the new setup. With our state titles in 3 weeks, I need to get this done fairly quickly.
Have read all info pertaining to rounding the beam arris, but is there a regulation/recommendation regarding the angle to cut the beam ends??



Hack

'Goodnight Nurse'
#1769
&
#1636
#275811 - 10/13/14 07:02 AM Re: beams [Re: Hack]  
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Pirate Offline
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Victoria Australia
Page 22

BUILDING INSTRUCTIONS FOR THE MOSQUITO CATAMARAN
(rewritten November 1995)


[Linked Image]


Yar, & this ere post be done without a sin'le drop o' rum passin' me lips

Kingy
started with Impara Cadet #3 / Mosquito #245
& now Mosquitos #1182 & #1740

#275840 - 10/15/14 01:28 AM Re: beams [Re: mousetrap]  
Joined: Oct 2010
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Phillip Offline
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Phillip  Offline
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South Oz
Hi Hack,
Thanks to Kingy for posting the suggested design from the Bldg Inst.
The cut-off angle suggested is the 25mm off-set. There is no regulation. This angle is for aesthetics. Any greater off-set may interfere with the location of the outer beam bolt.
The tension bolt (15 x 8 ss) is required as it removes the load from the inwale, it will be compressed if you don't have it.
Study the lower diagram; it illustrates fitting 5/4.8mm(3/16") monel or SS rivets. These rivets will reduce the sheer loads from the strap-to-beam attachment. Do not rely on just the tension and beam bolts to resist this sheer force.
The over-all length may vary but measure your existing beam for an indication. 2147mm was lifted off #1765 which has moderate hull width, wider than some, narrower than others. It has a maximum overall width of 2185mm.
I assume you will recycle major components.
Contact me direct through the MCASA if you need more info as the diagram is my production.
Phillip P

Last edited by Phillip; 10/15/14 01:30 AM.

Tortured ply is clearly beautiful.
Mozzie Aldebaran VI
1827
#275841 - 10/15/14 01:36 AM Re: beams [Re: Phillip]  
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Pirate Offline
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Pirate  Offline
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Victoria Australia
Originally Posted by Phillip
...Study the lower diagram ....


yeah sorry about that bit being in the shade of my hands and iPhone but it wasn't what I was after for hack at the time blush

if you click on the pic it should take you straight to photobucket for a larger version
wink



Last edited by Pirate; 10/15/14 01:37 AM. Reason: someone's been eating crisps and the 's' key is jaming

Yar, & this ere post be done without a sin'le drop o' rum passin' me lips

Kingy
started with Impara Cadet #3 / Mosquito #245
& now Mosquitos #1182 & #1740

#275842 - 10/15/14 01:44 AM Re: beams [Re: mousetrap]  
Joined: Nov 2012
Posts: 70
Hack Offline
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Hack  Offline
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Port Vincent, SA
Cheers Kingy and Phil,

I had a feeling the answer would be the one you provided, but I thought I should check.
Thanks for the useful diagram.

If I feature in this weeks race report, then you'll know the job was successful on Saturday.

Cheerio


Hack

'Goodnight Nurse'
#1769
&
#1636
#280593 - 09/24/15 04:42 AM Re: beams [Re: mousetrap]  
Joined: Apr 2009
Posts: 88
Matthew Dawson Offline
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Matthew Dawson  Offline
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Some more questions on beams.

What are the pros and cons of painting vs anodising vs powder coating?

Does anyone have any experience with non-anodised aluminium coated with Nyalic?
http://www.thesailboatshop.com.au/category-s/103.htm

Last edited by Matthew Dawson; 09/24/15 10:49 PM.

Cobra 570
Cobra 581
Mosquito 126
Arafura Cadet 738
#280595 - 09/24/15 06:17 AM Re: beams [Re: mousetrap]  
Joined: Feb 2012
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Schnoogie84 Offline
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I think the main benefit of anodising is that the whole beam (including the inside) is protected, whereas if you were to paint the beam, only the outside is. Anodising technically shouldn't change the weight of the beam compared with painting if you were really going for the nth percent on weight reduction?

#280604 - 09/24/15 03:27 PM Re: beams [Re: Matthew Dawson]  
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Pirate Offline
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Pirate  Offline
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Victoria Australia
as said..... anodising is full coverage protection whereas paint doesn't give that level of protection.

Another big disadvantage is that the paint chips quite easily, right in the area where the mast lays while you are attaching the shrouds prior to standing the mast or de-rigging the boat.

and one I hadn't figure on, the painted beam is slippery as heck when wet and that makes it a lot harder to clamber back on deck after a capsize..... ofcourse this isn't an issue if you don't get the boat wet or capsize it
grin


Yar, & this ere post be done without a sin'le drop o' rum passin' me lips

Kingy
started with Impara Cadet #3 / Mosquito #245
& now Mosquitos #1182 & #1740

#280606 - 09/24/15 10:51 PM Re: beams [Re: mousetrap]  
Joined: Apr 2009
Posts: 88
Matthew Dawson Offline
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Matthew Dawson  Offline
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Posts: 88
Thanks for the responses.

Is it true that anodised is slightly 'weaker'?


Cobra 570
Cobra 581
Mosquito 126
Arafura Cadet 738
#280609 - 09/25/15 05:28 AM Re: beams [Re: Matthew Dawson]  
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Pirate Offline
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Victoria Australia
no not at all... quite the opposite actually

Anodising is (simplest explanation) an electrical coating of the alloy much the same as chrome plating is, in the case of alloy, the anodising process forms a layer of aluminium oxide - Al203 (corundum), which is very hard, relatively inert, electrically insulating (which is why its suitable for salt water use wink ), and can absorb dyes to colour the alloy.

there are 3 main types of anodising.....

Sulphuric Acid Anodising -> used mainly for hard working areas where heavy use and wear n tear would normally cut down the protective surface in a short period of time, EG outdoor furniture, window frames etc etc

Hard Anodising -> significantly harder, thicker, denser films with a higher resistance to wear, corrosion, temperature effects etc.... your cars engine-bay will have components treated at this level

Chromic Acid Anodising -> These coatings are thin, and relatively soft and generally only used in specialised applications, the name plate on the trophies in your cabinet are chromic acid anodised.... good for looks and not much else

for beams on a boat, then the SULPHURIC ACID ANODISING is the best, its also the most commonly used form of anodising

cool

https://www.youtube.com/watch?v=O0GQPHh3Szk

wink


Yar, & this ere post be done without a sin'le drop o' rum passin' me lips

Kingy
started with Impara Cadet #3 / Mosquito #245
& now Mosquitos #1182 & #1740

#280612 - 09/25/15 06:56 AM Re: beams [Re: mousetrap]  
Joined: Apr 2009
Posts: 88
Matthew Dawson Offline
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Matthew Dawson  Offline
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Joined: Apr 2009
Posts: 88
Thanks Kingy. smile

Last edited by Matthew Dawson; 09/25/15 06:57 AM.

Cobra 570
Cobra 581
Mosquito 126
Arafura Cadet 738
#280626 - 09/27/15 12:19 AM Re: beams [Re: mousetrap]  
Joined: May 2007
Posts: 416
Matt_Stone Offline
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Matt_Stone  Offline
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anodising is the best, powder coating is good also, as said paint and powder coating adds a tiny bit of weight.

Key is the prep work to get a good finish. Sand with the grain (yes alloy has a grain) with 240 grit and sand with different grades of scour pads.

Matt

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