Going foamless

[logan944t]

Re: Going foamless

I use a 3M Scotch Brite Pad rubber banded around the air vent holes for the brushes to help filter the glass dust. Seems to really help in the longevity of the grinder.

Good idea-- I'll have to try that.


Ive had to stop for the day---it started raining while I was final shaping the transom.


I do want to post about something and relate my experience and opinion--and try to not start a long debate.

Ive read on Iboats--as well as other places --about thinning polyester resin/hardener with acetone and "soaking" the dry wood as much as possible in an attempt to get the resin to penetrate the wood (more than it would if it werent thinned) and therefore make it more rot resistant--almost a homebrew pressure treat.

I decided to see how far the polyester resin would penetrate.

I took a piece of 3/4" marine grade plywood and dried it for 4 weeks at an average of 20% humidity. I then mixed polyester resin and hardener according to the instructions( 1/4 oz hardener to 32 oz resin iirc). I then mixed in 2.5 oz of acetone. I applied liberally--and repeatedly until the resin didnt soak in any longer.

I left it sit for the night ( temps were 68 when I started and dipped to 45 overnight). In the morning the piece was still tacky-- much more than it should have been --so I set it in the sun ( temps were 70ish). The next day it was still tacky ( layup resin) but done. I left it set for 5 days.

Today I cut that piece in half. The most I was hoping for would be that the resin would have soaked to the first ply and the waterproof glue would stop it. It didnt get even that far. If I had to say how deep the thinned resin did penetrate it would be measured with machinists calipers--not a tape rule--less than a 1/32".

My opinion is that its not worth it. Just apply the resin full strength and move on.

 

[jones01m]

Re: Going foamless

I took a piece of 3/4" marine grade plywood and dried it for 4 weeks at an average of 20% humidity. I then mixed polyester resin and hardener according to the instructions( 1/4 oz hardener to 32 oz resin iirc). I then mixed in 2.5 oz of acetone. I applied liberally--and repeatedly until the resin didnt soak in any longer.

I left it sit for the night ( temps were 68 when I started and dipped to 45 overnight). In the morning the piece was still tacky-- much more than it should have been --so I set it in the sun ( temps were 70ish). The next day it was still tacky ( layup resin) but done. I left it set for 5 days.

Today I cut that piece in half. The most I was hoping for would be that the resin would have soaked to the first ply and the waterproof glue would stop it. It didnt get even that far. If I had to say how deep the thinned resin did penetrate it would be measured with machinists calipers--not a tape rule--less than a 1/32".

Man I love test data! Thanks for sharing your findings.

 

[Yacht Dr.]

Re: Going foamless

I took a piece of 3/4" marine grade plywood and dried it for 4 weeks at an average of 20% humidity. I then mixed polyester resin and hardener according to the instructions( 1/4 oz hardener to 32 oz resin iirc). I then mixed in 2.5 oz of acetone. I applied liberally--and repeatedly until the resin didnt soak in any longer.

I left it sit for the night ( temps were 68 when I started and dipped to 45 overnight). In the morning the piece was still tacky-- much more than it should have been --so I set it in the sun ( temps were 70ish). The next day it was still tacky ( layup resin) but done. I left it set for 5 days.

Today I cut that piece in half. The most I was hoping for would be that the resin would have soaked to the first ply and the waterproof glue would stop it. It didnt get even that far. If I had to say how deep the thinned resin did penetrate it would be measured with machinists calipers--not a tape rule--less than a 1/32".

My opinion is that its not worth it. Just apply the resin full strength and move on.

You are not really creating a Home brew Pressure Treat with your thinning of the resin. It would be comparable to Home brew Marine ply.

But you started out with Marine Ply .. I dont know of any threads that suggest you Treat Marine grade ply in such a fashion.

Marine ply has more piles of wood. No wonder your resin never got through the first Quality pile of wood ..

Try the same test on a 3/4" CDX sample and see what happens .. Ill bet you go through 3x the resin and have a Very different outcome.

Just saying mate..

YD.

 

[BillP]

Re: Going foamless

I applaud your empiracle testing! Clap, Clap, Clap. You have just started to learn fact from fiction that "wood saturation" is 99.99% hype. Even the most punky wood with resin poured on it will barely get past the surface...and that epoxy "saturated" rotted wood is not restored to any appreciable structural strength. New wood has even less grain penetration. If everyone did their own tests like you did nobody would be thinking "saturation". I've done it with all types of resin and woods and the results are alway the same. Resin attaches itself to the surface and that about as far as it penetrates. You have to use a microscope to see the penetration.

Bill P.

 

[logan944t]

Re: Going foamless

Try the same test on a 3/4" CDX sample and see what happens .. Ill bet you go through 3x the resin and have a Very different outcome.

Good idea since I was gonna make my deck outta cdx.



Spent about 3 hours grinding the transom blank to get a good fit ( about a 1/4" space on the sides) and discovered the transom skin on the boat at the very bottom is missing chunks. So Im gonna have to pack the cavity with PB--smooth it out--and lay in a layer of csm to tie it all back together again. THEN a full layer of csm between the plywood and the transom.

For as much time as I have spent on just on doing the transom the right way -- I think next time ( because of course theres gonna be another project ...)I will just bite the bullet and use a pourable transom.

 

[Woodonglass]

Re: Going foamless

Again.. bad advice .. the Armature and the brushes are encapsulated within the tool housing. Those Vents are too keep the tool COOL .. Do not even put your hand over the vents as they blow HOT OUT ! .. or you can if you like and Smoke your tool fast.


YD.

EDIT: Seriously lacking in courtesy and diplomacy. woody.

1. This is a family site. The use of foul or insulting language or the posting of any material not judged suitable by the Moderator Team is forbidden. Disagreements on any topic must be conducted in a polite manner using courteous language.

 

[chriscraft254]

Re: Going foamless

Wood, he is right, you should not be adding anything to the vents on a power tool. It will burn it up. Your sanders and grinders if well built will stay cool under prolonged use, this is because they inject cool air and keep the tool cool. I may not know much about boats, but tools are another thing.

Op, the Hitachi I recommended was for this exact reason, you will burn through 6 hf grinders before you burn through a good one. Not just that, you will see just how much vibration and tingling in the hands you have after using a cheap one for a extended period of time. Tools are one thing I make my living using. I have pretty much used them all as far as good quality tools. Only thing I have ever bought at "harbour junk" is sanding disks, and I never went back for those again.

 

[logan944t]

Re: Going foamless

Op, the Hitachi I recommended was for this exact reason, you will burn through 6 hf grinders before you burn through a good one. Not just that, you will see just how much vibration and tingling in the hands you have after using a cheap one for a extended period of time. ]

A big difference that Ive noticed between the dewalt I was using and the chicago electric that I just bought from HF is the torque. When you first pulled the trigger on the dewalt you had better hold on but once it got going it was smooth. If I used it for any length of time my hands would be sore-- from fighting the torque.The one I was using today ( Chicago Electric) feels rough with no snap to it-- and --yes-- my hands hurt from the vibration.

I fully expect to toss the cheap one after this boat is done. I didnt want to buy a good grinder just to gum it up with glass. I think I paid 40$ total for 2 hf grinder and 2 packs of assorted discs-- and I already tossed one of the 36 grit flapdiscs with todays use. I have a ton of tools ( literally--had to pay for shipping once) most of which are good quality. I have a mill and a lathe that I paid a pretty penny for -- but I know they will last and are repairable. My auto tools are inherited from my father and are not pretty, shiny or have GPS --but have lasted 30 or so years of his heavy use --and now mine.

I think there is a time and a place for both disposable tools and the lasting ones.

 

[BillP]

Re: Going foamless

The typical DIY doesn't need a high end tool to get through a couple of boat projects. Making a living with your tools is a totally different situation. I have a shop full of expensive, middle and cheap tools (Snapon to HF).One of the best buys has been the HF 6 speed x 3000 rpm x 7" sander/polisher. I bought it as a backkup when my industrial grade sander had parts on order. For $25 I'm impressed and it has been used for 10yrs on major boat projects. It grinds just like the big dog. The downside is the spindle is a different thread and accessories aren't plentiful. Also, the lightweight is a disadvantage when grinding horizontal surfaces...my other tool is 10lbs and the weight helps keep pressure when using 24 & 36 grit. Keep the fiberglass dust blown out of the motor for long life whether an expensive tool or not. I've burned up several grinders by not keeping them clean and it can happen in days, not weeks or months. Consider hf tools as disposable and enjoy the other $150 saved. Spend another $25 for another hf if you need to finish up something.

bp

 

[Yacht Dr.]

Re: Going foamless

A big difference that Ive noticed between the dewalt I was using and the chicago electric that I just bought from HF is the torque. When you first pulled the trigger on the dewalt you had better hold on but once it got going it was smooth.

I fully expect to toss the cheap one after this boat is done.

I think there is a time and a place for both disposable tools and the lasting ones.

I know this is not a tool debate thread.. but seeing as I am responding to logan ..

First .. I would Never buy another 'triggered 4.5"' grinder again. You have to constantly hold the trigger down ( hand cramps and hard to hold it in reaching grinds ). I Very much recommend the 'Switch' type small grinders.

Second.. I would never buy another 4.5" grinder without a 5/8" arbor. All of the Real Goodies are for a 5/8" arbor .

You are correct sir on the time and place for tools and their expense.

I have a cheapo grinder that is used for NOTHING but wire wheels. I dont need to press hard to prep keels or drives. I let wire wheels do the work. I dont use my 'glass grindin' grinders for wire wheel applications .. too fast and too much power for it. So yes .. there are uses for them cheap tools that you should not throw away .

Blowing out your tools with Clean DRY air is key to longevity. Do a quick blow off around the tool to get loose dust off..then do a Hard/close blow out Starting with the head vents of the tool and work your way down to the trigger of the tool ( I have seen many that dont think of blowing out the Trigger/switch which leads to trigger failure ).

Any moisture in the compressed air will kill your tool fast..Dry air is key.

OH.. one other thing .. I have gotten some of my best tools from a Pawn shop .. 40 bucks will get ya a bad looking grinder that is in Perfect condition if you know what your looking for .

YD.

 

[logan944t]

Re: Going foamless

First .. I would Never buy another 'triggered 4.5"' grinder again. You have to constantly hold the trigger down ( hand cramps and hard to hold it in reaching grinds ). I Very much recommend the 'Switch' type small grinders.

Cramps? BAH! Real men laugh at cramps!! ....and I agree!

OH.. one other thing .. I have gotten some of my best tools from a Pawn shop .. 40 bucks will get ya a bad looking grinder that is in Perfect condition if you know what your looking for .

Normally I would agree with this -- but around here pawn shops are asking almost retail--and Ive looked for years. Sometimes I can find a tool that is cheap because its on clearance or because noone knows what its used for--but in this area pawn shop pickins is slim.

Today I did a little grinding ( almost not worth getting in the suit) and then it was a patch on a thru-crack where the transom sat ( pretty sure this is one way to rot out a transom fast) and then a tab across the whole bottom where the transom meets the bottom hull.

I also have to say, I think Im in love. I mixed up my first batch of PB ever...and well it was just heaven. It stayed where I put it, didnt run off --and there was no disrespect whatsoever. I will have to caution people tho -- dont mix it in a breeze. It wasnt pretty. I used it to patch where a few chunks of glass came off in the transom skin --so it would be a smooth surface when I install the transom blank.

I think I like adding glass a whole lot more than ripping it out.

 

[logan944t]

Re: Going foamless

Test fit the transom blank last night--final fit this morning and drilled the holes out where the motor bolts on. Test clamped with 2x4's. Final glass is hardening ( had to cut the 3rd layer back because the cap would have hit the top of it--so the 3rd layer starts 3" from the top and continues to the bilge.) and hopefully will be installed in a few hours.

Im gonna be using csm between the blank and the transom skin. I would like to use a thin layer of pb--just to make sure all surfaces are covered. Is there a reason I shouldnt?

 

[Woodonglass]

Re: Going foamless

You should always use PB to glue the transom to the outer skin. Use a 1/4" toothed trowel to apply the PB to the transom and the outer skin and then clamp it. Not to hard, just enough to get some squeeze out. Use the squeeze out and some additional PB to fillet the edges. Check out the drawings in the link in my signature below.

 

[logan944t]

Re: Going foamless

Oh! You're the guy that had those diagrams-- thank you! I saved those to my desktop and been staring at them for months.

 

[oops!]

Re: Going foamless

i have been working lots lately as our season is just starting up.....

however i caught this....

You are not really creating a Home brew Pressure Treat with your thinning of the resin. It would be comparable to Home brew Marine ply.
YD.

i think the good doctor got his mirds wixed up or this thoughts mixed up with his typing fingers....

turning ply into marine grade by adding thinned resin is like turning lead into gold....it is not possible.....

dont even try.

i am typing this because i dont want out new readers to start thinking they can make thier own marine grade plywood by using thinned resin.

it cant happen....it wont happen......dont even try....

 

[oops!]

Re: Going foamless

The typical DIY doesn't need a high end tool to get through a couple of boat projects. Making a living with your tools is a totally different situation. I've burned up several grinders by not keeping them clean and it can happen in days, not weeks or months. Consider hf tools as disposable and enjoy the other $150 saved.

bp

our friend formerly from pluto really nailed it here.

the discussion on tools has been done many times over the years here.

the diy builder here that bought a boat with soft spots on the deck does not need to go buy a dewalt grinder to do this job.
if he loves his tools and has the use for using the grinder on many different projects....then fine......let him spend the money.

but to rough and scuff a hull......you dont need to spend a gazillion dollars for one project...

saving money is the key reason we are diy type guys !

 

[logan944t]

Re: Going foamless

Well....best laid plans...


I was hoping to get the blank installed this afternoon but I guess I didnt notice a few stray stiff glass fibers and after walking away the top of the blank has an air bubble all along the inner corner. So I have to grind the corner glass off and reglass tomorrow. I was more worried about the bottom --but that went flawlessly--compound corners and all.

 

[jones01m]

Re: Going foamless

logan,

Do you have any pictures?

 

[logan944t]

Re: Going foamless

Pictures!? You guys want everything!


Yea I have pics and will post later today-- for some reason the forum wont accept pics from my laptop-- so I have to use my wife's pc.

Got the bubbles ground off-- it wasnt as bad as it looked. Put another layer of csm along top to cover any place that wasnt covered.

Looking at the bucket --it looks like Ive used about 2 gals prepping the transom skin and the transom blank--for the total job so far.

 

[oops!]

Re: Going foamless

logan.....if you upload to a free photo hosting service like photo bucket.....

you can copy and paste the IMG tag to your reply....easy...and fast.

and 2 gals of bubbles is a lot...