diy acrylic question

[bracebldrs]

made my own wd/fuge and hob overflows
realy cool how acrylic bonds with weldon#3
just learning .filled up wd/fuge today 4 days
after glueing 48x14x16 with water 2 pin holes
i know i could sprikle shavings over leak and glue
but my question is do any of you diy people
silicone after for security ? your input would be
appretiated

 

[team2jndd]

I silicone all joints with a thin layer just incase. How do you drill yours? I havent been able to drill without cracking.

 

[team2jndd]

any chance you want to explain how you build the overflow boxes? Ive tried several times and cant seem to get them right.

 

[bchbum189]

weld on 16, its still an acrylic glue, but its thick and ment to seal gaps, dont put silicone on acrlic it doenst stick very well at all

 

[chipmaker]

A Silicone does not stick to acrylic very well and it wil let you down when you least expect it, plus it makes using solvent bonding glue like weldon at a later date a real &*(*% as it interferes with proper melting of acrylic which makes the bond. Weldon #16 can be filleted in corners if your paranid or just dissolve a little bit of acrylic material in some weldon 3 or 4 to make a thicker solution for pin hole repair. If the joints are free of air bubbles there is no need to do anything else to them as they are as reliable as a solid molded joint would be. If sufficient weldon #3 or 4 was used and joints were flat and relatively smooth, air bubbles should not exist and they should be just fine.

 

[bracebldrs]

SOYF Join Date: Jul 2005
Posts: 672
I silicone all joints with a thin layer just incase. How do you drill yours? I havent been able to drill without cracking.
i onlly have 1, 1/4in acrylic drill bit bought from construction
tool store and i use a roughter with gides temp clamped on
to prevent jumping around going slow .

 

[bchbum189]

dont drill close to egdes, as acrylic will always want to crack towards the nearest edge. I always run cool water over it while i drill to keep temps down. Try drilling half way threw and flipping it over and drilling from the otherside the rest of the way to avoid chips on the outside. Go slow and dont push down hard
and dont put silicone on acrylic, if you want to seal for extra assurance either buy weld on 16 or make ur own out of shavings, but not silicone

 

[chipmaker]

The big reason acrylic chips and cracks when drilling is the rake angle and point angle on typical drillbits is improper for drilling plastic. It needs to be reduced drastically on the rake angle and the point also needs to be reduced as well so its not as agressive and takes as big of bites when drilling nor have that tendency to pull th ebit trhough when it breaks through the other surface. No need for water. Its also good to drill with the piece firmly in contact and held down tight on say a piec eof plywood or other lonber or scrap wood.
I'll say it one more time, silicone is not intended to be used on acrylics.its a proven fact it does not hold and is destined to fail. Its not even suitable for a so called just in case deal..Either the joint is right or its not, if its not, make it right.............nothing like having bandaids holding everything together.

 

[bracebldrs]

yea your right .i do remember testing several
types of adhesives, local hardware store ones
even silicone on scrap pieces to find something
to bond acrylic silicone was the worst .well
i took a small elmers glue bottle, cleaned it out
filled it up 1/2 way with acrylic shavings from
table saw top off with weldon#3, shook it up
ran a nice bead on all joints.worked awsome!!!
maybe ill show pics tomarow to get input and advice
thanks for advice so far

 

[acrylic51]

Exactly right silicone doesn't bond very well with acrylic and if your having problems with pinholes the 16 is meant to solve that problem....some of that could be solved with better edge prep and good gluing procedure as well.....Melevs reef site gives good info on bonding acrylic....Should check it out sometime