At the gelcoat stage - help needed!!!

[morebass 17]

Re: At the gelcoat stage - help needed!!!

Oop's, I have to start by saying its great to have input from the likes of yourself and ondarvr. I know I can take everything you two say is the truth and nothing but the truth. I have to add that if it was'nt for you Oop's I would'nt be doing all this to my boat, ( not sure if i should love you or hate you lol ) as it was your hull extension thread that got me hooked and gave me the motivation to carry on. Not to mention what i learned from it as I knew nothing about boats apart from what way up they were meant to be. I think someone has stated this before but it should be mandatory for new members to read your thread as it will answer 99.9% of all questions from people.

I,ve not been able to catch up on your big build for a while now. Just been too busy sanding for the last 1,000,000,000 hours of my build. I was always one of the lurkers that followed your build, but i have to say my hat comes off to you for pulling it off. I would ask you to fill me in on the progress you've made in the last couple of month but i don't want to spoil this great book you have written, ( when is it getting published lol )

I would never disclaim anything ondarvr had to say, as you said he has probably forgoton more than we have ever learned, but you know your stuff as well , so its always good to hear from the experts.

I may still decide to spray it on but for the time being I am going to persevere with below the waterline with brush , roller , squeegy and just see if i can get comfortable applying it this way. I feel i should be able to but its early days yet. Well i would love to stay and chat but ive still got 598,987,035 hours of sanding to do. Hopefully more pics soon.

oop's & ondarvr thanks again and stay tuned.

Outback Jack thanks for the luck I'll need it and some more, good luck with yours

 

[morebass 17]

Re: At the gelcoat stage - help needed!!!

well based on the advise given and some serious thinking ( ah my head hurts now ) I will most likely spray the gelcoat on. I am going to finish what i have started below the waterline though to get the surface faired out again for spraying.
A couple of questions though about the choice of compressor - am i right in saying i will need a compressor that has at least 3HP and a tank size of 100l with an output of about 11cfm as most guns i see require this kind of output, or would this be overkill. I was thinking of hiring one but i think it will be more cost effective just buying one as i have more parts including the cap that will be getting sprayed ( possibly just paint though for the rest of the boat )
There has already been some info posted on this thread about tip size, should I just get the biggest I can find. edit - ( sorry just realized this has been answered . I have to read things a number of times for it to sink in - stupid me ) also has anyone have any experience with gravity fed vs suction guns or would either do the trick.

 

[Yacht Dr.]

Re: At the gelcoat stage - help needed!!!

Hi morebass 17 sorry for the late reply ..

Ive only seen a boat rolled out one time. It didnt work out too good for the owner.

From what I understand at this point..

You have tacky uncured gel. You would wipe off that uncured surface with acetone. Just wipe away..keep wiping with more clean rags. ( Please wear a respo and some good gloves ).

This is how I full spray gel..

1. Get an el-cheapo Harbor Frieght 2 QT pressure pot ( NOT HVLP ).
2. Mix your gelcoat with 25ish % MEK Solvent ( Not the MEKP ) . Its kinda hard to tell how much you would thin because gelcoats are not All the same in viscosity. You want it kinda like tomato soup out of the can before you warm it up.
3. Have your surface all ready to go ( wiped down with acetone .. masked off etc. ).
4. Suit up good. Respo,suit,gloves,goggles with the holes taped up.
5. Have a box of powdered latex gloves, A few gals of acetone, cups , stir sticks, rags, a brush ( for clean up ).
6. Mix up your gel ( approx 10 CC per quart ).
7. put that in your pressure pot and start shooting away. Use side to side spray patterns. Release the trigger at the ends of the swipe. Basically you pull the trigger all the way back when you start your first motion...then release the trigger stopping the fluid ( keep the air still going just not the fluid )..then pull the trigger when coming back on your pass.
8. When you run out of gel.. open the pot up and put a few cups of acetone in there..flush it.
9. mix some more gel and do that over and over untill you have a good couple thick coats on there.
10. Clean your gun well with acetone. When flushing the gun you want to turn off the air leading to your GUN. you should only have a pee stream comeing from the tip of your gun when flushing ( You will need to have a "cheater" valve hooked to the bottom end of the gun itself for adjusting the air pressure to full off at the gun). Its hard to explain .. Ill take some pics of my gun setup so you know what im talking about.
11. wait untill the gel is tacky to the finger but does not pull off..then spray over the gelcoat with PVA (Polyvinyl alcohol).
12.let cure for a day. .. Rinse off with water and start your sanding steps ( Dry or wet-dry is does not matter ).
13.Buff out.

I would suggest that you play with your gun with water to kinda get used to it before you shoot . rinse out with acetone when your done playing around.

Oh..and after your done flushing the gun with acetone..before you spray your PVA .. Flush the gun with WATER !. Then spray your PVA..then flush it again with WATER...then final flush with acetone. PVA and acetone turns to SNOT .

The reason I never release the trigger all the way while spraying ( shutting down the fluid but not the air ) is because if a chunck gets jammed up in the needle while the air is off you will get a solid stream of gelcoat coming out..NOT good lol.

Its really not that hard..but its hard to explain in full detail with all the tricks and stuff..sorry..

Any questions just fire away..

YD.

 

[morebass 17]

Re: At the gelcoat stage - help needed!!!

Thanks for the info Yacht Dr. - That is some great advise there, basically a how to from start to finish. Just a couple of questions though.

In your first step - "1. Get an el-cheapo Harbor Frieght 2 QT pressure pot ( NOT HVLP )." can you explain this gun in some more detail maybe even a pic of one, I understand HVLP is a High Volume Low Pressure setup but I have not came across a pressure pot before, I'm a bit of a newb when it comes to spraying.

Also what size of compressor would I need for this setup, would it just be the same type of comp as i would use with HVLP.

Is this step just adding thinner ? - 2. Mix your gelcoat with 25ish % MEK Solvent ( Not the MEKP )

and this is the catylist ? - 6. Mix up your gel ( approx 10 CC per quart )

thanks

 

[morebass 17]

Re: At the gelcoat stage - help needed!!!

Thanks for the info Yacht Dr. - That is some great advise there, basically a how to from start to finish. Just a couple of questions though.

In your first step - "1. Get an el-cheapo Harbor Frieght 2 QT pressure pot ( NOT HVLP )." can you explain this gun in some more detail maybe even a pic of one, I understand HVLP is a High Volume Low Pressure setup but I have not came across a pressure pot before, I'm a bit of a newb when it comes to spraying.

Also what size of compressor would I need for this setup, would it just be the same type of comp as i would use with HVLP.

Is this step just adding thinner ? - 2. Mix your gelcoat with 25ish % MEK Solvent ( Not the MEKP )

and this is the catylist ? - 6. Mix up your gel ( approx 10 CC per quart )

thanks

 

[morebass 17]

Re: At the gelcoat stage - help needed!!!

had a quick look at harbour freight, is this what you mean ( see attached pic ) the only problem with harbour freight is i dont think they will ship to the U.K. but i'm sure I'll find somewhere local who will supply similar equipment.

 

[lonnie t]

Re: At the gelcoat stage - help needed!!!

Yacht Dr, i dont think anyone could have explained that any better

 

[morebass 17]

Re: At the gelcoat stage - help needed!!!

I tried applying the gelcoat by roller and tipping with a brush on a small area on the transom, but there is no way i would get the finish i require doing it this way, i possibly could if i applied a considerable number of coats to allow for the amount of sanding that would be required but this is not cost or time efficient, so even although the stuff is designed for brush application and the rest of the U.K. seem to do it this way for wahatever strange reason. ( why do we Brits make things so hard for ourselves ) I am going to do it the logical way and spray this bad boy.

The project will probably be on hold for about a week or so untill I can source a decent compressor and equipment at a reasonable price, I will however be starting the soul destroying task of sanding all the gelcoat I have already applied, and as previously mentioned this will most likely involve sanding down to the substrate / original gelcoat in most areas.

As I said I can get a hold of sprayable gelcoat, not sure if this is just the same stuff i'm using apart from it will be already thinned for spray application, I will talk to my supplier for some more info on this. Although there may not be much progress in the next few days, try and stay tuned though.

 

[morebass 17]

Re: At the gelcoat stage - help needed!!!

Yacht Dr, i dont think anyone could have explained that any better

Yeah lonnie t your right, Its always a priveledge to have input from the extremly talented and knowledgable people like Yacht Dr, Ondarvr & Oop's. I know there are others that Ive not mentioned but as I am new to this site I'm not sure who they are yet.

 

[lonnie t]

Re: At the gelcoat stage - help needed!!!

same here ,im only a newbie theres so much on here i dont know where to start lol
im in the process of doin the floor in mine and while i fartin around i noticed theres been a bodgy spary job been done so looks like im goin have give it rub'n spray after im done (*&%*) , so i been takin note what these fellas been sayin and a priveledge it is

 

[morebass 17]

Re: At the gelcoat stage - help needed!!!

11. wait untill the gel is tacky to the finger but does not pull off..then spray over the gelcoat with PVA (Polyvinyl alcohol).

Am I right in saying that this step replaces the need for adding wax to the final coat of gel. As the PVA should seal the surface to make it air tight.

 

[morebass 17]

Re: At the gelcoat stage - help needed!!!

theres so much on here i dont know where to start lol

Your not kidding lonnie t, It is the best forum and site on the net, There is nothing even remotely close to this site where I am from.

It does'nt seem to matter how much of a newbie we are or how stupid the questions are that we ask, there is always friendly people on here that know their stuff that is willing to help.

 

[morebass 17]

Re: At the gelcoat stage - help needed!!!

I'm looking into which spray gun and compressor setup to use, There is so much to pick from and at the same time I am trying to do this as cheap as possible without reducing the quality of finish.

As Dr. Yacht suggests I should use a pressure pot setup and other people have suggested a cheap HVLP gun, so i'm a little confused as to what to go for. The pressure pot setup works out to be more expensive but from what I can see this will be better suited for spraying a full hull as I can mix and spray almost 2 Liters at a time whereas a gravity fed HVLP will only hold approx 0.5 Liters. Is there any other benefit of using the pressure pot setup ?

I am keeping an eye on this ebay listing
http://cgi.ebay.co.uk/Clarke-Paint-..._Body_Shop_Supplies_Paint&hash=item415807f118

It does not include a gun but from what I have read the guns that are used for HVLP are similar, it is the delivery to the gun that is different. What do you all think of this item, and my method of thinking, would it be suitable if I found a gun to match ?

Also just found this one too, A little expensive but if ithis is what is recomended then so be it.
http://cgi.ebay.co.uk/2-LITRE-PRESS..._Body_Shop_Supplies_Paint&hash=item5636541cd7

 

[j_k_bisson]

Re: At the gelcoat stage - help needed!!!

Ok the difference between the HVLP gun and the Pot system is that the pot system you presurize the holding tank forcing the thicker liquid out at a higher rate then the traditional HVLP guns. Also seeing you are spraying a very thick liquid (gel coat) it does not flow nicely though a traditional HVLP gun. It comes out very blochy and splatery.

Harbour Freight is our local "made in china" tool store. The tools are cheaply made and quality is where the sacrifice to make it cheap. But with this type of work you will probably through out all whole spray system when you are done the boat. Clogging and stuff. So don't buy an expensive setup. You might want a decent air compressor though. You will end up keeping it when you are donw for alot of years.

This is why you will see certain things we recomend high quality tools (Life time) and then Harbour freight tools(disposable).

 

[morebass 17]

Re: At the gelcoat stage - help needed!!!

that clears up a few questions, thanks j_k_bisson. I will be going for a half decent compressor maybe 2nd hand though. I will keep searching for a cheap pressure pot system since it will be most likely thrown out after gelling my hull.

All the pressure pot systems I see come with a much smaller gun tip though ( 1.5 - 2.0mm ) Should this tip be changed to something in the 4.0 - 5.0mm range. Or should the tip be smaller because of higher pressure in this setup.

Thanks again for the info.

 

[j_k_bisson]

Re: At the gelcoat stage - help needed!!!

That is a Yatch Dr question. I only use what they come with from Harbour freight. Here is the true master. He has played with the different tips and can tell you what you need. Send him a PM. He is pretty good at responding if nothing is going on. But its busy time of the year for him. Everyone wnats their boats done now! You know how it goes.

I seam to recall he like the 2.0-2.5mm Check his threads he started. I think he mentions this topic in one of them.

 

[morebass 17]

Re: At the gelcoat stage - help needed!!!

Thanks again j_k_bisson I'll check out his threads for more info. I'm not really too keen on sending pm's just now as I don't want to hassle anyone, he must have loads of people asking for help at this time of year. I'm sure I'll find the info I need somewhere on this amazing site.

 

[oops!]

Re: At the gelcoat stage - help needed!!!

thatpressure pot is the real deal bud....thats what we all use.
you will have to get a regulator between the pot and gun as well. the regulator on that rig is for the pot
get the biggest tip you can......2.5 or even 3.

i dont know the viscosity of the gook you have there....so i cant comment on the gun and pot pressures.....the thicker the gook...the higher the pot pressure.
5 lbs is LOTS.
and you want lots of air from your gun

 

[morebass 17]

Re: At the gelcoat stage - help needed!!!

Thanks Oop's I'll try and find somewhere that sells something similar.

I will check the spec's for the product I will be using for the viscosity and I'll do some homework on pot pressure. I think I will mess about with the gel, and try spraying some plywood or something first.

Is the most important factor going to be a constant and consistent flow, or is the pot pressure more impoortant than that.

 

[DanielR]

Re: At the gelcoat stage - help needed!!!

Where can someone buy spray gun tips in sizes 2.0mm + for gun that comes with Harbor Freight pressure pot?
I spray Devilbiss so i go to their site for the accessories, but I cant seem to find any tips for HF gun since i dont know whats compatible.

thanks