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View Full Version : Most agressive compound for Gelcoat?



imported_smprince1
03-09-2008, 09:04 PM
I just worked on a 1971 fiberglass boat that needed to have some serious cutting to remove the amount of chalky/faded gel coat.



The 3M Marine Rubbing Compound did OK, but I was wondering if there was another compound suitable for gel coat that was even more agressive than that.



Thanks.

execdetails
03-10-2008, 08:30 PM
The pink 3m heavy duty is the most you want to use. If it is extremely oxidized it might be easier to wet sand the gelcoat and then compound it

imported_smprince1
03-10-2008, 08:37 PM
Thanks for the reply and info.



This is what I used: Product Catalog (http://solutions.3m.com/wps/portal/3M/en_US/Marine/Home/Products/Catalog/?PC_7_RJH9U5230GE3E02LECIE20S4K7_nid=04P9Q33CRLgs9 NQK7NZ8TZglLFGNCH1ZTQbl)



I did end up wet sanding by hand, but man it wore me out.

execdetails
03-11-2008, 07:19 AM
Wet sanding is miserable but sometimes it is the best way and the results are excellent.

Chris@Optimum
03-11-2008, 08:47 AM
I love Ardex`s Smartcut: you`d be totally impressed with what you get from 1 pass.

steck
03-11-2008, 09:40 AM
lengthy but interesting none the less :



well, after seeing those pics of the pachanga - in your other post...i see what your up against.



i did a 1985 `sleekercraft something or other boat`...cant remember the real name (but an 80mph rocket).



gelcoat is simply an enigma for me. i wetsanded. i compounded. i polished. i waxed. it was an improvement but I was looking for more.:hairpull



i heard the ole rumour about silicones and their effect (albeit short lived) on gelcoat.



so for the sake of experimentation, i grabbed my megs endurance tire shine - the thick purple stuff..put in generously on a damp sponge and went over a section of the boat. it looked good (shiny and wet). a little greasy, but it looked like it never did before. i waited 30 minutes to let this product `soak in` and wiped off excess. i honestly couldnt believe my eyes. no amount of wax i used made the boat look like that. it looked better than new.



this is an old trick of the trade, i`ve heard of people using armour all tire foam on the sides of their hulls (gel coat) for a quick `shiner up`er`.



regardless, boat owner was happy went he took it away !



i learned that gel coat is porous. if you work your compounds/polishes too long (dry) than all that product is being absorbed into the gelcoat..making removal difficult and keeping a `dull` look to the gel coat.



to do that boat all over again would be 1/ wetsand 2000 grit 2/ light polish (megs marine stuff) 3/ use a wax with a high silicone content 4/ add some silicone for a little `wow` factor 5/ forget about it !!



i aint tellin anyone to use tire foam on their boats, or condoning it for that matter...i just thought i`d pass along my experience with gel coat.

DETAILKING
03-11-2008, 09:36 PM
For hulls that are very oxidized I use 3M super duty compound with a wool pad. Works great.



I agree with others, once a gel coat gets porous, it makes waxing very difficult, it tends to absorb the product and takes a lot of effort to remove the residue.

imported_smprince1
03-12-2008, 05:38 AM
OK, sounds like the 3M Marine Compound is the most agressive / most popular stuff to use for heavily oxidized boats.



Is there anything special about the wool pad make up for figerglass? I used 100% wool and a rotary, about 2200rpm. It did cut, it just took quite a few passes and I was wondering if there was a more agressive approach that was safe and effective.



BTW .... over 100 views and no responses to my other post on that 37 year old Pachanga .... does it look that bad? I`m always open to suggestions/comments .... I mean, that`s why I post here :hifive:

SShine
03-12-2008, 02:52 PM
For hulls that are very oxidized I use 3M super duty compound with a wool pad. Works great.



I agree with others, once a gel coat gets porous, it makes waxing very difficult, it tends to absorb the product and takes a lot of effort to remove the residue.



you pretty much cant wax gelcoat unless you remove most if not all of the oxidation.



A little trick I use if the gelcoat keeps sucking up the wax after numerous passes with compound and polish, I will add some polish (more like a glaze) to the wax, seems to help from staining.



Has anyone used Meguiars new compound yet? It seems to be like M105 but for gelcoat.



http://www.meguiars.com/estore/products/product_M9101.jpg