Posts by mosaad

choosing your timber

Quote from Ramon

Tu amigo quizás confundió la resina con cola de carpintero expansiva, la foto es COLA POLIURETANO LIQUIDO PU para madera
(hay varios fabricantes)
este adhesivo no necesita catalizador es resistente al agua salada y ambientes marinos, solo hay que limpiar con acetona
las partes a unir.
Te puedo garantizar que se romperá antes la madera, que abrirse por la union, la espuma se quita con una espátula o cúter es muy blanda.

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I have used poly long time before and gun success but i have to pay more dollar to the planner because no gap or tolerance is allow tight clamp is a must and if not delamination will occur however epoxy can fill any gap with sufficient results .

Quote from Silentstoning

A couple of comments to add to this. In the original post there is mention of acetone. I try not to use that unless necessary. I believe Riffe had some delamination problems a while back due to acetone. I use my air compressor and make sure there is no sawdust or anything left on the wood before epoxying. This ensures the wood does not have any solvent to mess with your epoxy mix. Additionally, I did not see too much mention of filler. For laminating I see filler as a must.

Dave, regarding your question on how much pressure is too much I keep going until there is minimal pressure. If you are trying to tighten your clamps and you are using force, that is too much. You don't want to squeeze out your epoxy, otherwise, you end up with gaps that you won't necessarily see which means a weaker bond and possible delamination problems in the future.

how much the 403 filler 150 gram can give you epoxy to mayonnaise shape? I mean 150 gram fiber = X mL mayonnaise epoxy ?
my question for estimate the quantity I need to purchase online

if you want to make your stock ready with balanced drilled holes before going to the sea to get the accurate lead needed I just make very simple experiment and want to share it to everyone here ,

need simple tools :big water jar , your wood sample ,weight and digital scale

attach the weight to your wood till sink or what ever then measure the required weight and multiply to your gun weight
ex. I have padouk and billinga
padouk weight is 69 gram will sink with 25 gram of ss ratio is 0.3623
billinga weight 96 gram and need 41 gram ss ratio is 0.427
so when I make gun with 1kg padouk I need approxi. or around 362 gram
gun with 1.5kg billinga I need approxi. or around 640 gram

Is that correct and how to calculate for seawater ?

actually I am going to make a something similar to seawolf design with some modification ,for retainer I have 2.5mm wire SS can be bend to the required angles and fit to wood as I did before and this easy other plan to either use a tube 13.7mm OD and thick 2 mm cut and shaped or square tube 12.7mm 1.65mm thick cut and shape ,
Josh you have open other point regarding the flip ,as all roller I have seen when you pull your trigger the band will be preloaded already and it will hit the retainer in all ways unless I miss something here ,I think making a square notch at end of gun similar to a Greek designer won't be good look but need to think for other way to prevent the flip of the muzzle

List of data sheets available - Tropix 7 - CIRAD

this site is saving a lot of time for everyone looking for wood to choose in our hobbies ,just give my post like guys

but using notch spear with roller not giving accurate shot !band will bush notch little up when spear near the retainer and shot will be low ,is that correct?

I have seen a design of roller speargun using a tube as a retainer ,they just cut it half as a section and fix it to the end of the muzzle they leave a gap to keep allowance for the shark fin ,I like the idea and thinking to do same with 1/4 in pipe 1/16 thick but here my question is their a possibility the spear shark fin will rotate left or right and hit the retainer after pushing the trigger ? it can rip it off with spear high speed or it won't?

in design program u can get center of mass ,mass and volume if u can estimate the weigh u need for neutral u will know where to add in your stock easily ,may be for manual works its not important but for CNC router it will save time

:):) ,u are genius

can we use the specific wood gravity to estimate required balancing leads?
ex. iroko is 0.64 so w expecting 0.36 weight ratio ,2 kg of wood need 720 g to get neutral =500g spear + SS accessories + lead if needed

is it near the accurate or far a way ?

what about 17-7 PH u can get more hardness result than 17-4 PH

If it 45 rock hardness i ll buy from him also ,some country you can get labor charge very low compared to usa ,so its cheaper to fabricate rather than import from outside ,by the way what the material used by rabitech or other african seller its quench tempered steel but which alloy ?

I was searching in fabrication processes and get ideas want to share here regarding making a spears ,cost will be from labor charges only and not from materials here the way I think its how they do ,may be there is some tricks but the idea is same

get either 17-4 or 15-5 alloy in normal condition
weld or machine what you want on it
straightness the bar within the tolerance ranges
heat treat your spear in the accurate temperature (u search for it )
get your spear ready

is it simple like that ?

ALL THE WOODS BELOW CAN BE USED FOR BUILD BUT FIRST 7 CAN GIVE A MORE STABLE WOOD ,IS IT TRUE?

TEAK
PADAUK
KOSIPO
Canarywood
Merbau
Cedar
AFRICAN MAHOGANY
UTILE/SIPO
ROSEWOOD
BLACK CHERRY
IROKO
DABEMA
AFRORMOSIA
WHITE OAK
Black Walnut
Sapele
Cocobolo
Black Mesquite
Jarrah

anyone have a detail dimension for the common euro spears ?I have for american already .

Beuchat Flat GT Tahitian Super Steel Spear 7 mm with Shark Fins

Anyone know what material they use?strong enough like quench steel or another type of SS ?

I shoot red snapper and emperor by the new 110 ,it work great and perfect balanced sink slowly muzzle heavy

balance of roller was difficult

coated by epoxy
varnish